What is the most abundant amino acid in the human body?
Glutamine
Glutamine is the most abundant naturally occurring, nonessential amino acid in the human body, and one of the few amino acids that can directly cross the blood–brain barrier. Humans obtain glutamine through catabolism of proteins in foods they eat. In states where tissue is being built or repaired, like growth of babies, or healing from wounds or severe illness, glutamine becomes conditionally essential.
Protein (nutrient)
The table below presents the most important food groups as protein sources, from a worldwide perspective. It also lists their respective performance as source of the commonly limiting amino acids, in milligrams of limiting amino acid per gram of total protein in the food source. The table reiterates the need for a balanced mix of foods to ensure adequate amino acid source.
Alanine
Alanine is a nonessential amino acid, meaning it can be manufactured by the human body, and does not need to be obtained through the diet. Alanine is found in a wide variety of foods, but is particularly concentrated in meats.
Arginine
In humans, arginine is classified as a semiessential or conditionally essential amino acid, depending on the developmental stage and health status of the individual. Preterm infants are unable to synthesize or create arginine internally, making the amino acid nutritionally essential for them. Most healthy people do not need to supplement with arginine because it is a component of all protein-containing foods and can be synthesized in the body from glutamine via citrulline.
Antithrombin
Antithrombin has a half-life in blood plasma of around 3 days. 
The normal antithrombin concentration in human blood plasma is high at approximately 0.12 mg/ml, which is equivalent to a molar concentration of 2.3 μM.
Antithrombin has been isolated from the plasma of a large number of species additional to humans. As deduced from protein and cDNA sequencing, cow, sheep, rabbit and mouse antithrombins are all 433 amino acids in length, which is one amino acid longer than human antithrombin. The extra amino acid is thought to occur at amino acid position 6. Cow, sheep, rabbit, mouse, and human antithrombins share between 84 and 89% amino acid sequence identity. Six of the amino acids form three intramolecular disulfide bonds, Cys8-Cys128, Cys21-Cys95, and Cys248-Cys430.
They all have four potential N-glycosylation sites. These occur at asparagine (Asn) amino acid numbers 96, 135, 155, and 192 in humans and at similar amino acid numbers in other species. All these sites are occupied by covalently attached oligosaccharide side-chains in the predominant form of human antithrombin, α-antithrombin, resulting in a molecular weight for this form of antithrombin of 58,200. The potential glycosylation site at asparagine 135 is not occupied in a minor form (around 10%) of antithrombin, β-antithrombin (see Figure 1).
Carnitine
Carnitine (β-hydroxy-γ-"N"-trimethylaminobutyric acid, 3-hydroxy-4-"N","N","N"-trimethylaminobutyrate) is a quaternary ammonium compound involved in metabolism in most mammals, plants and some bacteria. Carnitine may exist in two isomers, labeled -carnitine and -carnitine, as they are optically active. At room temperature, pure carnitine is a white powder, and a water-soluble zwitterion with low toxicity. Carnitine only exists in animals as the -enantiomer, and -carnitine is toxic because it inhibits the activity of -carnitine. Carnitine, derived from an amino acid, is found in nearly all organisms and animal tissue. Carnitine is the generic expression for a number of compounds that include L-carnitine, acetyl-L-carnitine, and propionyl-L-carnitine. It is most accumulated in cardiac and skeletal muscles as it accounts for 0.1% of its dry matter. It was first derived from meat extracts in 1905, therefore the name carnitine is derived from Latin ""carnus"" or flesh. The body synthesizes enough carnitine from lysine side chains to keep up with the needs of energy production in the body as carnitine acts as a transporter of long-chain fatty acids into the mitochondria to be oxidized and produce energy. Some individuals with genetic or medical disorders (like preterm infants) cannot make enough, so this makes carnitine a conditionally essential nutrient for them.
Glutamic acid
Glutamic acid is produced on the largest scale of any amino acid, with an estimated annual production of about 1.5 million tons in 2006. Chemical synthesis was supplanted by the aerobic fermentation of sugars and ammonia in the 1950s, with the organism "Corynebacterium glutamicum" (also known as "Brevibacterium flavum") being the most widely used for production. Isolation and purification can be achieved by concentration and crystallization; it is also widely available as its hydrochloride salt.
Amino acid
The phrase "branched-chain amino acids" or BCAA refers to the amino acids having aliphatic side chains that are non-linear; these are leucine, isoleucine, and valine. Proline is the only proteinogenic amino acid whose side-group links to the α-amino group and, thus, is also the only proteinogenic amino acid containing a secondary amine at this position. In chemical terms, proline is, therefore, an imino acid, since it lacks a primary amino group, although it is still classed as an amino acid in the current biochemical nomenclature, and may also be called an "N-alkylated alpha-amino acid".
Human nutrition
Proteins consist of amino acids in different proportions. The most important aspect and defining characteristic of protein from a nutritional standpoint is its amino acid composition. Amino acids which an animal cannot synthesize on its own from smaller molecules are deemed essential. The synthesis of some amino acids can be limited under special pathophysiological conditions, such as prematurity in the infant or individuals in severe catabolic distress, and those are called conditionally essential.
TMEM249
There exist a number of SNPs for TMEM 249 in humans. The mutations are scattered for the most part, with the largest changes in amino acids occurring in the domain of unknown function.
Complete protein
It was once thought that plant sources of protein are deficient in one or more amino acids, and so vegetarian diets had to specifically combine foods during meals, which would create a complete protein. However, the most recent position of the Academy of Nutrition and Dietetics is that protein from a variety of plant foods eaten during the course of a day supplies enough essential amino acids when caloric requirements are met. Normal physiological functioning of the body is possible if one obtains enough protein and sufficient amounts of each amino acid from a plant-based diet. In fact, the highest PDCAAS scores are not given to commonly eaten meat products, but rather to animal-derived vegetarian foods like milk and eggs and the vegan food soy protein isolate.
Proteinogenic amino acid
In eukaryotes, there are only 21 proteinogenic amino acids, the 20 of the standard genetic code, plus selenocysteine. Humans can synthesize 12 of these from each other or from other molecules of intermediary metabolism. The other nine must be consumed (usually as their protein derivatives), and so they are called essential amino acids. The essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine (i.e. H, I, L, K, M, F, T, W, V).
Multiple Epidermal Growth Factor-like Domains 8
MEGF8 is composed of either 2845 amino acids (Isoform 1) or 2778 amino acids (Isoform 2). Isoform 2 undergoes a 67 amino acid removal from 700-766, which accounts for its shortened length; otherwise, the two isoforms are identical. Using SAPS, a Statistical Analysis of Protein Sequence software, amino acid bias was able to be determined. Isoform one is rich in cysteine and glycine, and deficient in isoleucine and lysine. Isoform 2 of MEGF8 was found to have very high levels of cysteine, moderately high levels of glycine, and low levels of isoleucine and lysine.
The high levels of cysteine residues contributes to the numerous disulfide bonds found in the mature protein's folded structure. Overall, MEGF8 has a pH between 6.4 and 7.0, depending on the organism's sequence. Human MEGF8's pH is 6.4. This nearly neutral pH enables the protein to fold properly and inhibits denaturation. The twenty most conserved amino acids, found through a multiple sequence alignment of 20 orthologs, were found to be located in the CUB and transmembrane domains.
Essential amino acid
The amino acids that are essential in the human diet were established in a series of experiments led by William Cumming Rose. The experiments involved elemental diets to healthy male graduate students. These diets consisted of cornstarch, sucrose, butterfat without protein, corn oil, inorganic salts, the known vitamins, a large brown "candy" made of liver extract flavored with peppermint oil (to supply any unknown vitamins), and mixtures of highly purified individual amino acids. The main outcome measure was nitrogen balance. Rose noted that the symptoms of nervousness, exhaustion, and dizziness were encountered to a greater or lesser extent whenever human subjects were deprived of an essential amino acid.
Alpha-Ketovaleric acid
α-Ketovaleric acid is a keto acid that is found in human blood. Unlike related keto acids, it is not an intermediate or metabolite associated with amino acids and its origin is unknown.
Aspartic acid
Aspartic acid (symbol Asp or D; the ionic form is known as aspartate), is an α-amino acid that is used in the biosynthesis of proteins. Similar to all other amino acids it contains an amino group and a carboxylic acid. Its α-amino group is in the protonated –NH form under physiological conditions, while its α-carboxylic acid group is deprotonated −COO under physiological conditions. Aspartic acid has an acidic side chain (CHCOOH) which reacts with other amino acids, enzymes and proteins in the body. Under physiological conditions (pH 7.4) in proteins the side chain usually occurs as the negatively charged aspartate form, −COO. It is a non-essential amino acid in humans, meaning the body can synthesize it as needed. It is encoded by all the codons GAU and GAC.
Amino acid-based formula
Amino acid-based formula, also known as an elemental formula, is a type of hypoallergenic infant formula made from individual amino acids. Amino acids are the building blocks of protein and together they form the protein requirements in formula needed for growth and development. The amino acids are in the simplest form, making it easy for the body to process and digest. "Neocate", "EleCare" and "Nutramigen Puramino" are the more commonly encountered brands of amino acid-based formula in the US.
Hemolymph
Arthropod hemolymph contains high levels of free amino acids. Most amino acids are present but their relative concentrations vary from species to species. Concentrations of amino acids also vary according to the arthropod stage of development. An example of this is the silkworm and its need for glycine in the production of silk.
Sports nutrition
The supplement, Creatine, may be helpful for well-trained athletes to increase exercise performance and strength in relation with their dietary regimen. The substance glutamine, found in whey fiber supplements, is the most abundant free amino acid found in the human body. It is considered that glutamine may have a possible role in stimulated anabolic processes such as muscle glycogen and protein synthesis, for well-trained and well-nourished athletes. Other popular studies done on supplements include androstenedione, chromium, and ephedra. The findings show that there are no substantial benefits from the extra intake of these supplements, yet higher health risks and costs.
Essential amino acid
Although plants tend to have less protein per weight than animal sources such as eggs or milk, they are nevertheless "complete" in that, as a whole, they contain all of the amino acids essential in human nutrition. The same is true for algae and marine phytoplankton. Eating various plant foods over an extended period of time can provide a protein of higher biological value. Certain native combinations of foods, such as corn and beans, soybeans and rice, or red beans and rice, contain the essential amino acids necessary for humans in adequate amounts. However, the idea that plant-based foods must be combined to provide humans all of the essential amino acids is outdated. The official position of the Academy of Nutrition and Dietetics is that protein from a variety of plant foods eaten during the course of a day supplies enough of all essential amino acids when caloric requirements are met.
Tryptophan
Amino acids, including tryptophan, are used as building blocks in protein biosynthesis, and proteins are required to sustain life. Many animals (including humans) cannot synthesize tryptophan: they need to obtain it through their diet, making it an essential amino acid. Tryptophan is among the less common amino acids found in proteins, but it plays important structural or functional roles whenever it occurs. For instance, tryptophan and tyrosine residues play special roles in "anchoring" membrane proteins within the cell membrane. In addition, tryptophan functions as a biochemical precursor for the following compounds (see also figure to the right):
Protein
Most microorganisms and plants can biosynthesize all 20 standard amino acids, while animals (including humans) must obtain some of the amino acids from the diet. The amino acids that an organism cannot synthesize on its own are referred to as essential amino acids. Key enzymes that synthesize certain amino acids are not present in animals—such as aspartokinase, which catalyses the first step in the synthesis of lysine, methionine, and threonine from aspartate. If amino acids are present in the environment, microorganisms can conserve energy by taking up the amino acids from their surroundings and downregulating their biosynthetic pathways.
Human nutrition
Most fatty acids are not essential, meaning the body can produce them as needed, generally from other fatty acids and always by expending energy to do so. However, in humans, at least two fatty acids are essential and must be included in the diet. An appropriate balance of essential fatty acids – omega-3 and omega-6 fatty acids – seems also important for health, though definitive experimental demonstration has been elusive. Both of these "omega" long-chain polyunsaturated fatty acids are substrates for a class of eicosanoids known as prostaglandins, which have roles throughout the human body. They are hormones, in some respects. The omega-3 eicosapentaenoic acid (EPA), which can be made in the human body from the omega-3 essential fatty acid alpha-linolenic acid (LNA), or taken in through marine food sources, serves as a building block for series 3 prostaglandins (e.g. weakly inflammatory PGE3). The omega-6 dihomo-gamma-linolenic acid (DGLA) serves as a building block for series 1 prostaglandins (e.g. anti-inflammatory PGE1), whereas arachidonic acid (AA) serves as a building block for series 2 prostaglandins (e.g., pro-inflammatory PGE 2). Both DGLA and AA can be made from the omega-6 linoleic acid (LA) in the human body, or can be taken in directly through food. An appropriately balanced intake of omega-3 and omega-6 partly determines the relative production of different prostaglandins: one reason a balance between omega-3 and omega-6 is believed important for cardiovascular health. In industrialized societies, people typically consume large amounts of processed vegetable oils, which have reduced amounts of the essential fatty acids along with too much of omega-6 fatty acids relative to omega-3 fatty acids.
Gamma-Aminobutyric acid
GABA is also found in plants. It is the most abundant amino acid in the apoplast of tomatoes. Evidence also suggests a role in cell signalling in plants.
Amino acid replacement
Some amino acids are more likely to be replaced. One of the factors that influences this tendency is physicochemical distance. Example of a measure of amino acid can be Graur's Stability Index. The assumption of this measure is that the amino acid replacement rate and protein's evolution is dependent on the amino acid composition of protein. Stability index "S" of an amino acid is calculated based on physicochemical distances of this amino acid and its alternatives than can mutate through single nucleotide substitution and probabilities to replace into these amino acids. Based on Grantham's distance the most immutable amino acid is cysteine, and the most prone to undergo exchange is methionine. 
Evolution of proteins is slower than DNA since only nonsynonymous mutations in DNA can result in amino acid replacements. Most mutations are neutral to maintain protein function and structure. Therefore, the more similar amino acids are, the more probable that they will be replaced. Conservative replacements are more common than radical replacements, since they can result in less important phenotypic changes. On the other hand, beneficial mutations, enhancing protein functions are most likely to be radical replacements. Also, the physicochemical distances, which are based on amino acids properties, are negatively correlated with probability of amino acids substitutions. Smaller distance between amino acids indicates that they are more likely to undergo replacement.
CAPZA2
CapZ-alpha2 is a 33.0 kDa protein composed of 286 amino acids. "CAPZA2" is located on human chromosome 7, position q31.2-q31.3. The primary sequence of CapZ-alpha2 contains three C-terminal, regularly spaced leucines at positions 258, 262 and 266 found in consensus sequence of KxxxLxxE/DLxxALxxK/R that are critical for actin binding; these residues are conserved within the CapZ-beta isoform. CapZ-alpha2 is 85% identical to CapZ-alpha1, and differ by a small number of key amino acids; 21 amino acid differences perpetrate isoform specificity. CapZ-alpha2 is expressed in a variety of tissues, including cardiac muscle and skeletal muscle, where it caps sarcomeric actin at Z-discs; the ratio of CapZ-alpha2 to CapZ-alpha1 varies significantly among different tissues.
Non-proteinogenic amino acids
In meteorites and in prebiotic experiments (e.g. Miller–Urey experiment) many more amino acids than the twenty standard amino acids are found, several of which at higher concentrations than the standard ones: it has been conjectured that if amino acid based life were to arise in parallel elsewhere in the universe, no more than 75% of the amino acids would be in common. The most notable anomaly is the lack of aminobutyric acid.
Protein (nutrient)
There are nine essential amino acids which humans must obtain from their diet in order to prevent protein-energy malnutrition and resulting death. They are phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine. There has been debate as to whether there are 8 or 9 essential amino acids. The consensus seems to lean towards 9 since histidine is not synthesized in adults. There are five amino acids which humans are able to synthesize in the body. These five are alanine, aspartic acid, asparagine, glutamic acid and serine. There are six conditionally essential amino acids whose synthesis can be limited under special pathophysiological conditions, such as prematurity in the infant or individuals in severe catabolic distress. These six are arginine, cysteine, glycine, glutamine, proline and tyrosine.
Lysine
Lysine is one of the nine essential amino acids in humans. The human nutritional requirements varies from ~60 mg·kg·d in infancy to ~30 mg·kg·d in adults. This requirement is commonly met in a western society with the intake of lysine from meat and vegetable sources well in excess of the recommended requirement. In vegetarian diets, the intake of lysine is less due to the limiting quantity of lysine in cereal crops compared to meat sources. Given the limiting concentration of lysine in cereal crops, it has long been speculated that the content of lysine can be increased through genetic modification practices. Often these practices have involved the intentional dysregulation of the DAP pathway by means of introducing lysine feedback-insensitive orthologues of the DHDPS enzyme. These methods have met limited success likely due to the toxic side effects of increased free lysine and indirect effects on the TCA cycle. Plants accumulate lysine and other amino acids in the form of seed storage proteins, found within the seeds of the plant, and this represents the edible component of cereal crops. This highlights the need to not only increase free lysine, but also direct lysine towards the synthesis of stable seed storage proteins, and subsequently, increase the nutritional value of the consumable component of crops. Whilst genetic modification practices have met limited success, more traditional selective breeding techniques have allowed for the isolation of "Quality Protein Maize", which has significantly increased levels of lysine and tryptophan, also an essential amino acid. This increase in lysine content is attributed to an "opaque-2" mutation that reduced the transcription of lysine lacking zein related seed storage proteins and, as a result, increased the abundance of other proteins that are rich in lysine. Commonly, to overcome the limiting abundance of lysine in livestock feed, industrially produced lysine is added. The industrial process includes the fermentative culturing of "Corynebacterium glutamicum" and the subsequent purification of lysine.
Human serum albumin
The albumin is the predominant protein in most body fluids, its Cys34 represents the largest fraction of free thiols within body. The albumin Cys34 thiol exists in both reduced and oxidized forms. In plasma of healthy young adults, 70–80% of total HSA contains the free sulfhydryl group of Cys34 in a reduced form or mercaptoalbumin (HSA-SH). However, in pathological states characterized by oxidative stress and during the aging process, the oxidized form, or non-mercaptoalbumin (HNA), could predominate. The albumin thiol reacts with radical hydroxyl (.OH), hydrogen peroxide (HO) and the reactive nitrogen species as peroxynitrite (ONOO.), and have been shown to oxidize Cys34 to sulfenic acid derivate (HSA-SOH), it can be recycled to mercapto-albumin; however at high concentrations of reactive species leads to the irreversible oxidation to sulfinic (HSA-SO2H) or sulfonic acid (HSA-SO3H) affecting its structure. Presence of reactive oxygen species (ROS), can induce irreversible structural damage and alter protein activities.
Vegetarianism
Protein intake in vegetarian diets is lower than in meat diets but can meet the daily requirements for most people. Studies at Harvard University as well as other studies conducted in the United States, United Kingdom, Canada, Australia, New Zealand and various European countries,
confirmed vegetarian diets provide sufficient protein intake as long as a variety of plant sources are available and consumed. Pumpkin seeds, peanut butter, hemp seed, almonds, pistachio nuts, flaxseed, tofu, oats, soybeans, walnuts, are great sources of protein for vegetarians. Proteins are composed of amino acids, and a common concern with protein acquired from vegetable sources is an adequate intake of the essential amino acids, which cannot be synthesised by the human body. While dairy and egg products provide complete sources for ovo-lacto vegetarian, several vegetable sources have significant amounts of all eight types of essential amino acids, including lupin beans, soy, hempseed, chia seed, amaranth, buckwheat, pumpkin seeds spirulina, pistachios, and quinoa. However, the essential amino acids can also be obtained by eating a variety of complementary plant sources that, in combination, provide all eight essential amino acids (e.g. brown rice and beans, or hummus and pita, though protein combining in the same meal is not necessary). A 1994 study found a varied intake of such sources can be adequate.
Alpha-Amanitin
"alpha"-Amanitin or α-amanitin is a cyclic peptide of eight amino acids. It is possibly the most deadly of all the amatoxins, toxins found in several species of the mushroom genus "Amanita", one being the death cap ("Amanita phalloides") as well as the destroying angel, a complex of similar species, principally "A. virosa" and "A. bisporigera". It is also found in the mushrooms "Galerina marginata" and "Conocybe filaris". The oral of amanitin is approximately 0.1 mg/kg for rats.
PRR23C
Proline is predicted to be the most abundant amino acid in proline-rich protein 23C "Homo sapiens". In comparison to the prevalence of amino acids in other human proteins, it is predicted that proline-rich protein 23C "Homo sapiens" has a higher abundance of proline along with very low abundances of asparagine, threonine, and lysine. Orthologs for this protein are predicted to also have a high abundance of proline.
Titin
Titin is the third most abundant protein in muscle (after myosin and actin), and an adult human contains approximately 0.5 kg of titin. With its length of ~27,000 to ~33,000 amino acids (depending on the splice isoform), titin is the largest known protein. Furthermore, the gene for titin contains the largest number of exons (363) discovered in any single gene, as well as the longest single exon (17,106 bp).
Protein (nutrient)
Protein is a nutrient needed by the human body for growth and maintenance. Aside from water, proteins are the most abundant kind of molecules in the body. Protein can be found in all cells of the body and is the major structural component of all cells in the body, especially muscle. This also includes body organs, hair and skin. Proteins are also used in membranes, such as glycoproteins. When broken down into amino acids, they are used as precursors to nucleic acid, co-enzymes, hormones, immune response, cellular repair, and other molecules essential for life. Additionally, protein is needed to form blood cells.
Omega-3 fatty acid
Three omega−3 fatty acids are important in human physiology, α-linolenic acid (18:3, "n"-3; ALA), eicosapentaenoic acid (20:5, "n"-3; EPA), and docosahexaenoic acid (22:6, "n"-3; DHA). These three polyunsaturates have either 3, 5, or 6 double bonds in a carbon chain of 18, 20, or 22 carbon atoms, respectively. As with most naturally-produced fatty acids, all double bonds are in the "cis"-configuration, in other words, the two hydrogen atoms are on the same side of the double bond; and the double bonds are interrupted by methylene bridges (--), so that there are two single bonds between each pair of adjacent double bonds.
Non-proteinogenic amino acids
In biochemistry, non-coded or non-proteinogenic amino acids are those not naturally encoded or found in the genetic code of any organism.
Despite the use of only 22 amino acids (21 in eukaryotes) by the translational machinery to assemble proteins (the proteinogenic amino acids), over 140 amino acids are known to occur naturally in proteins and thousands more may occur in nature or be synthesized in the laboratory.
Many non-proteinogenic amino acids are noteworthy because they are;
Omega-3 fatty acid
Brain function and vision rely on dietary intake of DHA to support a broad range of cell membrane properties, particularly in grey matter, which is rich in membranes. A major structural component of the mammalian brain, DHA is the most abundant omega−3 fatty acid in the brain. It is under study as a candidate essential nutrient with roles in neurodevelopment, cognition, and neurodegenerative disorders.
Magnesium in biology
Mg is the fourth-most-abundant metal ion in cells (per moles) and the most abundant free divalent cation — as a result, it is deeply and intrinsically woven into cellular metabolism. Indeed, Mg-dependent enzymes appear in virtually every metabolic pathway: Specific binding of Mg to biological membranes is frequently observed, Mg is also used as a signalling molecule, and much of nucleic acid biochemistry requires Mg, including all reactions that require release of energy from ATP. In nucleotides, the triple-phosphate moiety of the compound is invariably stabilized by association with Mg in all enzymatic processes.
Human serum albumin
Human serum albumin is the serum albumin found in human blood. It is the most abundant protein in human blood plasma; it constitutes about half of serum protein. It is produced in the liver. It is soluble in water and monomeric.
Dicarboxylic aminoaciduria
Dicarboxylic aminoaciduria is a rare form of aminoaciduria (1:35 000 births) which is an autosomal recessive disorder of urinary glutamate and aspartate due to genetic errors related to transport of these amino acids. Mutations resulting in a lack of expression of the "SLC1A1" gene, a member of the solute carrier family, are found to cause development of dicarboxylic aminoaciduria in humans. SLC1A1 encodes for EAAT3 which is found in the neurons, intestine, kidney, lung, and heart. EAAT3 is part of a family of high affinity glutamate transporters which transport both glutamate and aspartate across the plasma membrane.
Low-protein diet
The daily requirement for humans to remain in nitrogen balance is relatively small. The median human adult requirement for good quality protein is approximately 0.65 gram per kilogram body weight per day and the 97.5 percentile is 0.83 grams per kilogram body weight per day. Children require more protein, depending on the growth phase. A 70 kg adult human who was in the middle of the range would require approximately 45 grams of protein per day to be in nitrogen balance. This would represent less than 10% of kilocalories in a notional 2,200 kilocalorie ration. William Cumming Rose and his team studied the essential amino acids, helping to define minimum amounts needed for normal health. For adults, the recommended minimum amounts of each essential amino acid varies from 4 to 39 milligrams per kilogram of body weight per day. To be of good quality, protein only needs to come from a wide variety of foods; there is neither a need to mix animal and plant food together nor a need to complement specific plant foods, such as rice and beans. The notion that such specific combinations of plant protein need to be made to give good quality protein stems from the book "Diet for a Small Planet". Plant protein is often described as incomplete, suggesting that they lack one or more of the essential amino acids. Apart from rare examples, such as Taro, each plant provides an amount of all the essential amino acids. However, the relative abundance of the essential amino acids is more variable in plants than that found in animals, which tend to be very similar in essential amino acid abundance, and this has led to the misconception that plant proteins are deficient in some way.
Lysine
Good sources of lysine are high-protein foods such as eggs, meat (specifically red meat, lamb, pork, and poultry), soy, beans and peas, cheese (particularly Parmesan), and certain fish (such as cod and sardines). Lysine is the limiting amino acid (the essential amino acid found in the smallest quantity in the particular foodstuff) in most cereal grains, but is plentiful in most pulses (legumes). A vegetarian or low animal protein diet can be adequate for protein, including lysine, if it includes both cereal grains and legumes, but there is no need for the two food groups to be consumed in the same meals.
Amino acid
When taken up into the human body from the diet, the 20 standard amino acids either are used to synthesize proteins and other biomolecules or are oxidized to urea and carbon dioxide as a source of energy. The oxidation pathway starts with the removal of the amino group by a transaminase; the amino group is then fed into the urea cycle. The other product of transamidation is a keto acid that enters the citric acid cycle. Glucogenic amino acids can also be converted into glucose, through gluconeogenesis. Of the 20 standard amino acids, nine (His, Ile, Leu, Lys, Met, Phe, Thr, Trp and Val) are called essential amino acids because the human body cannot synthesize them from other compounds at the level needed for normal growth, so they must be obtained from food. In addition, cysteine, taurine, tyrosine, and arginine are considered semiessential amino-acids in children (though taurine is not technically an amino acid), because the metabolic pathways that synthesize these amino acids are not fully developed. The amounts required also depend on the age and health of the individual, so it is hard to make general statements about the dietary requirement for some amino acids. Dietary exposure to the non-standard amino acid BMAA has been linked to human neurodegenerative diseases, including ALS.
Arachidonic acid
Arachidonic acid is a polyunsaturated fatty acid present in the phospholipids (especially phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositides) of membranes of the body's cells, and is abundant in the brain, muscles, and liver. Skeletal muscle is an especially active site of arachidonic acid retention, accounting for roughly 10-20% of the phospholipid fatty acid content typically.
Omega-6 fatty acid
Linoleic acid (18:2, "n"−6), the shortest-chained omega-6 fatty acid, is one of many essential fatty acids and is categorized as an essential fatty acid because the human body cannot synthesize it. Mammalian cells lack the enzyme omega-3 desaturase and therefore cannot convert omega-6 fatty acids to omega-3 fatty acids. Closely related omega-3 and omega-6 fatty acids act as competing substrates for the same enzymes. This outlines the importance of the proportion of omega-3 to omega-6 fatty acids in a diet.
Amino acid replacement
where "c" = composition, "p" = polarity, and "v" = molecular volume; and are constants of squares of the inverses of the mean distance for each property, respectively equal to 1.833, 0.1018, 0.000399. According to Grantham's distance, most similar amino acids are leucine and isoleucine and the most distant are cysteine and tryptophan.
Arginine
Arginine is a conditionally essential amino acid in humans and rodents, as it may be required depending on the health status or lifecycle of the individual. For example, while healthy adults can supply their own requirement for arginine, immature and rapidly growing individuals require arginine in their diet, and it is also essential under physiological stress, for example during recovery from burns, injury, and sepsis, or when the small intestine and kidneys, which are the major sites of arginine biosynthesis, have been damaged. It is, however, an essential amino acid for birds, as they do not have a urea cycle. For some carnivores, for example cats, dogs and ferrets, arginine is essential, because after a meal, their highly efficient protein catabolism produces large quantities of ammonia which need to be processed through the urea cycle, and if not enough arginine is present, the resulting ammonia toxicity can be lethal. This is not a problem in practice, because meat contains sufficient arginine to avoid this situation.
Tau protein
In humans, the MAPT gene for encoding tau protein is located on chromosome 17q21, containing 16 exons. The major tau protein in the human brain is encoded by 11 exons. Exons 2, 3 and 10 are alternatively spliced that lead to formation of six tau isoforms. In human brain, tau proteins constitute a family of six isoforms with a range of 352-441 amino acids. Tau isoforms are different in either zero, one, or two inserts of 29 amino acids at the N-terminal part (exon 2 and 3), and three or four repeat-regions at the C-terminal part (exon 10). Thus, the longest isoform in the CNS has four repeats (R1, R2, R3 and R4) and two inserts (441 amino acids total), while the shortest isoform has three repeats (R1, R3 and R4) and no insert (352 amino acids total).
Taste
The savory taste (known in Japanese as "umami") was identified by Japanese chemist Kikunae Ikeda of Tokyo Imperial University, which signals the presence of the amino acid L-glutamate, triggers a pleasurable response and thus encourages the intake of peptides and proteins. The amino acids in proteins are used in the body to build muscles and organs, transport molecules (hemoglobin), antibodies, and the organic catalysts known as enzymes. These are all critical molecules, and as such it is important to have a steady supply of amino acids, hence the pleasurable response to their presence in the mouth.
Aminoacylase 1 deficiency
Aminoacylase 1 (ACY1: EC 3.5.14) is a zinc binding enzyme which hydrolyzes N-acetyl amino acids into the free amino acid and acetic acid. Of the N-actyl amino hydrolyzing enzymes, aminoacylase 1 is the most common.
FAM149A
As stated above, FAM149A is made up of 482 amino acids. The most common amino acid is serine which makes up 9.8% of the gene. The least common amino acids are tryptophan and cysteine which each make up only 1.2% of the gene. The only recurring combination of amino acids in the protein is SLAS which occurs from amino acids 234-237 and from 324-327. In addition, the Isoelectric Point of FAM149A is 9.891999
Serine
-serine was thought to exist only in bacteria until relatively recently; it was the second amino acid discovered to naturally exist in humans, present as a signaling molecule in the brain, soon after the discovery of -aspartate. Had amino acids been discovered in humans sooner, the glycine site on the NMDA receptor might instead be named the -serine site. Apart from central nervous system, -serine plays a signaling role in peripheral tissues and organs such as cartilage, kidney and corpus cavernosum.
Asparagine
Asparagine (symbol Asn or N), is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO form under biological conditions), and a side chain carboxamide, classifying it as a polar (at physiological pH), aliphatic amino acid. It is non-essential in humans, meaning the body can synthesize it. It is encoded by the codons AAU and AAC.
Nutritional neuroscience
When protein is consumed, it is broken down into amino acids. These amino acids are used to produce many things like neurotransmitters, enzymes, hormones, and chromosomes. Proteins known as complete proteins contain all eight of the essential amino acids. Meat, cheese, eggs, and yogurt are all examples of complete proteins. Incomplete proteins contain only some of the eight essential amino acids and it is recommended that people consume a combination of these proteins. Examples of incomplete proteins include nuts, seeds, legumes, and grains. When animals are fed a diet deficient in essential amino acids, uncharged tRNAs accumulate in the anterior piriform cortex signaling diet rejection [105]. The body normally interconverts amino acids to maintain homeostasis, but muscle protein can be catabolized to release amino acids during conditions of amino acid deficiency. Disruption of amino acid metabolism can affect brain development and neurophysiology to affect behavior. For example, fetal protein deficiency decreases the number of neurons in the CA1 region of the hippocampus.
Cytochrome c
Cytochrome c has a primary structure consisting of a chain of about 100 amino acids. Many higher-order organisms possess a chain of 104 amino acids. The sequences of cytochrome c in humans is identical to that of chimpanzees (our closest relatives), but differs more from that of horses.
Monosodium glutamate
Monosodium glutamate (MSG, also known as sodium glutamate) is the sodium salt of glutamic acid, one of the most abundant naturally occurring non-essential amino acids. Glutamic acid is found naturally in tomatoes, grapes, cheese, mushrooms and other foods.
Amino sugar
In organic chemistry, an amino sugar (or more technically a 2-amino-2-deoxysugar) is a sugar molecule in which a hydroxyl group has been replaced with an amine group. More than 60 amino sugars are known, with one of the most abundant being "N"-Acetyl--glucosamine, which is the main component of chitin.
Threonine
As an essential amino acid, threonine is not synthesized in humans, and needs to be present in proteins in the diet. Adult humans require about 20 mg/kg body weight/day. In plants and microorganisms, threonine is synthesized from aspartic acid via α-aspartyl-semialdehyde and homoserine. Homoserine undergoes "O"-phosphorylation; this phosphate ester undergoes hydrolysis concomitant with relocation of the OH group. Enzymes involved in a typical biosynthesis of threonine include:
2-Arachidonoylglycerol
2-AG, unlike anandamide (another endocannabinoid), is present at relatively high levels in the central nervous system; it is the most abundant molecular species of monoacylglycerol found in mouse and rat brain (~5-10 nmol/g tissue). Detection of 2-AG in brain tissue is complicated by the relative ease of its isomerization to 1-AG during standard lipid extraction conditions. It has been found in maternal bovine as well as human milk.
Essential fatty acid
Mammals lack the ability to introduce double bonds in fatty acids beyond carbon 9 and 10, hence ω-6 linoleic acid (18:2,9,12), abbreviated LA (18:2n-6), and the ω-3 linolenic acid (18:3,9,12,15), abbreviated ALA (18:3n-3), are essential for humans in the diet. In humans, arachidonic acid (20:4,5,8,11,14, abbreviated 20:4n-6) can be synthesized from LA by alternative desaturation and chain elongation.
William Cumming Rose
At Illinois, Rose focused his research work on amino acid metabolism and nutrition. He found that the 19 amino acids then known were not sufficient for growth, and this led to his discovery in 1935 of the last of the common amino acids, α-amino-β-hydroxy-n-butyric acid, later named threonine. His studies also distinguished the amino acids that are absolutely essential from those that are necessary only for optimal growth. His studies further led him to the point where it was "practicable to evaluate proteins in terms of their ability to meet human needs." In June 1949 he published "Amino Acid Requirements of Man".
IFFO1
IFFO in human is located on the minus strand at Chromosome 12p13.3. The protein contains 17,709 nucleotide bases that encodes for 570 amino acids. The basal isoelectric point is 4.83. "IFFO1" contains a highly conserved filament domain that spans 299 amino acids from amino residue 230 to 529. This region has been identified as pfam00038 conserved protein domain family. Due to alternative splicing, there are 7 isoforms of IFFO1 in humans with 10 typical coding exons.
Amino acid
Because all amino acids contain amine and carboxylic acid functional groups, they share amphiprotic properties. Below pH 2.2, the predominant form will have a neutral carboxylic acid group and a positive α-ammonium ion (net charge +1), and above pH 9.4, a negative carboxylate and neutral α-amino group (net charge −1). But at pH between 2.2 and 9.4, an amino acid usually contains both a negative carboxylate and a positive α-ammonium group, as shown in structure (2) on the right, so has net zero charge. This molecular state is known as a zwitterion, from the German "" meaning "hermaphrodite" or "hybrid". The fully neutral form (structure (1) on the left) is a very minor species in aqueous solution throughout the pH range (less than 1 part in 10). Amino acids exist as zwitterions also in the solid phase, and crystallize with salt-like properties unlike typical organic acids or amines.
ADAM7
Human ADAM7 contains a sequence of 756 amino acids. Numerous mammalian orthologs are currently known. The largest portion of ADAM7 resides in the extracellular space. A short helical transmembrane sequence anchors the sequence while a short cytoplasmic sequence exists. This is consistent and expected as the protein has a secretory function.
Casamino acid
Casamino acids are either found in the Daptacel brand DTaP vaccine or used in its manufacture.
Casamino acid is a hydrochloric acid hydrolysate of casein. It supplies a completely hydrolyzed protein nitrogen source. It contains a small amount of cystine. Tryptophan and vitamins are destroyed by the acid treatment. The remaining amino acids (in varying amounts) are a source of nutrients for various microorganisms. Amino acids are highly soluble and suitable for use in tissue culture. Salt content is typically 30-40%.
Enaptin
Enaptin is a nuclear envelope protein found in human myocytes and synapses, which is made up of 8,797 amino acids. Enaptin is involved in the maintenance of nuclear organization and structural integrity, tethering the cell nucleus to the cytoskeleton by interacting with the nuclear envelope and with F-actin in the cytoplasm.
Valine
Valine (symbol Val or V) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO form under biological conditions), and a side chain isopropyl group, making it a non-polar aliphatic amino acid. It is essential in humans, meaning the body cannot synthesize it: it must be obtained from the diet. Human dietary sources are foods that contain protein, such as meats, dairy products, soy products, beans and legumes. It is encoded by all codons starting with GU (GUU, GUC, GUA, and GUG).
Bile acid
Cholic acid, 3α,7α,12α-trihydroxy-5β-cholan-24-oic acid, the most abundant bile acid in humans and many other species, was discovered before chenodeoxycholic acid. It is a tri-hydroxy-bile acid with 3 hydroxyl groups (3α, 7α and 12α). In its synthesis in the liver, 12α hydroxylation is performed by the additional action of CYP8B1. As this had already been described, the discovery of chenodeoxcholic acid (with 2 hydroxyl groups) made this new bile acid a "deoxycholic acid" in that it had one fewer hydroxyl group than cholic acid.
D-amino acid oxidase activator
D-amino acid oxidase activator (DAOA, also known as G72) is a protein enriched in various parts of brain, spinal cord, and testis. DAOA is thought to interact with D-amino acid oxidase, a peroxisomal enzyme, and its gene was associated with schizophrenia in a number of studies. In separate studies it has been shown to confer susceptibility to bipolar disorder. Therefore, it has been important in researching whether the Kraepelinian dichotomy is genuine. The gene itself was discovered during an investigation of chromosomal 13q22-q34 region, which was previously linked to schizophrenia. G72 is transcribed into several proteins due to alternative splicing; the longest protein is called LG72 and consists of 153 amino acids. Although the protein was initially found to interact with DAO in yeast 2-hybrid experiment, one recent in vivo experiment showed LG72 presence only in mitochondria and failed to confirm the interaction.
QRICH2
QRICH2 protein is 1663 amino acids long, and 10.9% of the amino acids are Glutamine (Q). 38% of the QRICH2 protein secondary structure is alpha-helix, 39% is beta-sheet and 13% is turning. The human tissue type with the highest level of QRICH2 expression is testis, and this result is confirmed by the Gene Expression Profile for mouse and dog too. The subcellular location of QRICH2 protein is in the nucleus. QRICH2 is a soluble protein, its average hydrophobicity is -0.5995. QRICH2 protein interact with a number of other proteins including SSSCA1, TSSC1, GAPDH, NUP98 and SNAI1.
Glutamic acid
Glutamic acid (symbol Glu or E) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is non-essential in humans, meaning the body can synthesize it. It is also an excitatory neurotransmitter, in fact the most abundant one, in the vertebrate nervous system. It serves as the precursor for the synthesis of the inhibitory gamma-aminobutyric acid (GABA) in GABA-ergic neurons.
Amino acid
Amino acids are used for a variety of applications in industry, but their main use is as additives to animal feed. This is necessary, since many of the bulk components of these feeds, such as soybeans, either have low levels or lack some of the essential amino acids: lysine, methionine, threonine, and tryptophan are most important in the production of these feeds. In this industry, amino acids are also used to chelate metal cations in order to improve the absorption of minerals from supplements, which may be required to improve the health or production of these animals.
Nutrition
Most fatty acids are non-essential, meaning the body can produce them as needed, generally from other fatty acids and always by expending energy to do so. However, in humans, at least two fatty acids are essential and must be included in the diet. An appropriate balance of essential fatty acids—omega-3 and omega-6 fatty acids—seems also important for health, although definitive experimental demonstration has been elusive. Both of these "omega" long-chain polyunsaturated fatty acids are substrates for a class of eicosanoids known as prostaglandins, which have roles throughout the human body. They are hormones, in some respects. The omega-3 eicosapentaenoic acid (EPA), which can be made in the human body from the omega-3 essential fatty acid alpha-linolenic acid (ALA), or taken in through marine food sources, serves as a building block for series 3 prostaglandins (e.g., weakly inflammatory PGE3). The omega-6 dihomo-gamma-linolenic acid (DGLA) serves as a building block for series 1 prostaglandins (e.g. anti-inflammatory PGE1), whereas arachidonic acid (AA) serves as a building block for series 2 prostaglandins (e.g. pro-inflammatory PGE 2). Both DGLA and AA can be made from the omega-6 linoleic acid (LA) in the human body, or can be taken in directly through food. An appropriately balanced intake of omega-3 and omega-6 partly determines the relative production of different prostaglandins, which is one reason why a balance between omega-3 and omega-6 is believed important for cardiovascular health. In industrialized societies, people typically consume large amounts of processed vegetable oils, which have reduced amounts of the essential fatty acids along with too much of omega-6 fatty acids relative to omega-3 fatty acids.
Tryptophan synthase
Tryptophan synthase is commonly found in Eubacteria, Archaebacteria, Protista, Fungi, and Plantae. It is absent from animals such as humans. Tryptophan is one of the twenty standard amino acids and one of nine essential amino acids for humans. As such, tryptophan is a necessary component of the human diet.
Glutaric aciduria type 1
While GCDH deficiency is a rare disease, GLO deficiency is the most common of metabolic diseases affecting children, limiting ascorbic acid biosynthesis to a minute fraction of what other non-primate species synthesize. It was thus called by OMIM (Online Mendeleian Inheritance in Man) a "public" error of metabolism. Ascorbic acid (Vitamin C) is a necessary cofactor for the utilization of lysine in collagen synthesis. Collagen, the most abundant protein in the human body, requires great amounts of lysine, the most abundant amino acids in proteins. Ascorbic acid, the main hydroxyl radical quencher, works as the cofactor providing the hydroxyl radical required to collagen cross-linking; lysine thus becomes hydroxylysine.
Amino acid
The alpha amino acids are the most common form found in nature, but only when occurring in the -isomer. The alpha carbon is a chiral carbon atom, with the exception of glycine which has two indistinguishable hydrogen atoms on the alpha carbon. Therefore, all alpha amino acids but glycine can exist in either of two enantiomers, called or amino acids, which are mirror images of each other ("see also Chirality"). While -amino acids represent all of the amino acids found in proteins during translation in the ribosome, -amino acids are found in some proteins produced by enzyme posttranslational modifications after translation and translocation to the endoplasmic reticulum, as in exotic sea-dwelling organisms such as cone snails. They are also abundant components of the peptidoglycan cell walls of bacteria, and -serine may act as a neurotransmitter in the brain. -amino acids are used in racemic crystallography to create centrosymmetric crystals, which (depending on the protein) may allow for easier and more robust protein structure determination. The and convention for amino acid configuration refers not to the optical activity of the amino acid itself but rather to the optical activity of the isomer of glyceraldehyde from which that amino acid can, in theory, be synthesized (-glyceraldehyde is dextrorotatory; -glyceraldehyde is levorotatory).
In alternative fashion, the "(S)" and "(R)" designators are used to indicate the absolute stereochemistry. Almost all of the amino acids in proteins are "(S)" at the α carbon, with cysteine being "(R)" and glycine non-chiral. Cysteine has its side chain in the same geometric position as the other amino acids, but the "R/S" terminology is reversed because of the higher atomic number of sulfur compared to the carboxyl oxygen gives the side chain a higher priority, whereas the atoms in most other side chains give them lower priority.
Essential fatty acid interactions
Arachidonic acid (AA) is a 20-carbon ω-6 conditionally essential fatty acid. It sits at the head of the "arachidonic acid cascade" – more than 20 different signalling paths that control a wide array of bodily functions, but especially those functions involving inflammation, cell growth and the central nervous system. Most AA in the human body derives from dietary linoleic acid (another essential fatty acid, 18:2 ω-6), which is derived from nuts, seeds, vegetable oils and animal fats.
Boletus edulis
A comparative study of the amino acid composition of eleven Portuguese wild edible mushroom species showed "Boletus edulis" to have the highest total amino acid content, about 2.3 g per 100 g of dried mushroom. This total includes a full complement of 20 essential and nonessential amino acids. Analysis of the free amino acids (that is, those not bound up in protein) revealed glutamine and alanine to be the principal amino acids (each about 25% of total compounds); a separate analysis concluded that lysine is another predominant compound.
Dopamine
The direct precursor of dopamine, -DOPA, can be synthesized indirectly from the essential amino acid phenylalanine or directly from the non-essential amino acid tyrosine. These amino acids are found in nearly every protein and so are readily available in food, with tyrosine being the most common. Although dopamine is also found in many types of food, it is incapable of crossing the blood–brain barrier that surrounds and protects the brain. It must therefore be synthesized inside the brain to perform its neuronal activity.
Alpha-Linolenic acid
Although the best source of ALA is seeds, most seeds and seed oils are much richer in an "n"−6 fatty acid, linoleic acid. Exceptions include flaxseed (must be ground for proper nutrient absorption) and chia seeds. Linoleic acid is the other essential fatty acid, but it, and the other "n"−6 fatty acids, compete with "n"−3s for positions in cell membranes and have very different effects on human health. There is a complex set of essential fatty acid interactions.
HIPK2
The HIPK2 protein is 1198 amino acids in length and has a molecular weight of 130.97 kilodaltons. The most abundant amino acids in the protein are serine, threonine and alanine, which make up approximately 30 percent of the proteins total amino acid count. The structure of the protein in its native form is unstable. The protein is made up of several regions which directly relate to its function, regulation, and localization. The protein kinase domain is 330 amino acids long and is located near the N-terminus of the protein. In addition to its kinase domain, HIPK2 has two nuclear localization signals, a SUMO interaction motif, an auto-inhibitory domain a transcriptional co-repression domain, and several interaction domains, including one for p53. While there are signals targeting HIPK2 to nuclear speckles, there is also a speckle retention sequence that causes HIPK2 to remain in the nuclear speckles. The auto-inhibitory domain, which contains an ubiquitylation site at the K1182 residue is located at the C-terminus.
Sialic acid
Sialic acid is a generic term for the "N"- or "O"-substituted derivatives of neuraminic acid, a monosaccharide with a nine-carbon backbone. It is also the name for the most common member of this group, N-acetylneuraminic acid (Neu5Ac or NANA). Sialic acids are found widely distributed in animal tissues and to a lesser extent in other organisms, ranging from fungi to yeasts and bacteria, mostly in glycoproteins and gangliosides (they occur at the end of sugar chains connected to the surfaces of cells and soluble proteins). That is because it seems to have appeared late in evolution. However, it has been observed in "Drosophila" embryos and other insects and in the capsular polysaccharides of certain strains of bacteria. Generally, plants do not contain or display sialic acids . In humans the brain has the highest sialic acid concentration, where these acids play an important role in neural transmission and ganglioside structure in synaptogenesis. In general, the amino group bears either an acetyl or a glycolyl group, but other modifications have been described. These modifications along with linkages have shown to be tissue specific and developmentally regulated expressions, so some of them are only found on certain types of glycoconjugates in specific cells. The hydroxyl substituents may vary considerably; acetyl, lactyl, methyl, sulfate, and phosphate groups have been found. The term "sialic acid" (from the Greek for saliva, "σίαλον" / "sialon") was first introduced by Swedish biochemist Gunnar Blix in 1952.
Docosahexaenoic acid
DHA is the most abundant omega-3 fatty acid in the brain and retina. DHA comprises 40% of the polyunsaturated fatty acids (PUFAs) in the brain and 60% of the PUFAs in the retina. Five percent of the weight of a neuron's plasma membrane is composed of DHA.
Amino acid synthesis
A fundamental problem for biological systems is to obtain nitrogen in an easily usable form. This problem is solved by certain microorganisms capable of reducing the inert N≡N molecule (nitrogen gas) to two molecules of ammonia in one of the most remarkable reactions in biochemistry. Ammonia is the source of nitrogen for all the amino acids. The carbon backbones come from the glycolytic pathway, the pentose phosphate pathway, or the citric acid cycle.
Animal nutrition
Proteins are the basis of many animal body structures (e.g. muscles, skin, and hair). They also form the enzymes which control chemical reactions throughout the body. Each molecule is composed of amino acids which are characterized by the inclusion of nitrogen and sometimes sulfur. The body requires amino acids to produce new proteins (protein retention) and to replace damaged proteins (maintenance). As there is no protein or amino acid storage provision, amino acids must be present in the diet. Excess amino acids are discarded, typically in the urine. For all animals, some amino acids are "essential" (an animal cannot produce them internally) and some are "non-essential" (the animal can produce them from other nitrogen-containing compounds). A diet that contains adequate amounts of amino acids (especially those that are essential) is particularly important in some situations: during early development and maturation, pregnancy, lactation, or injury (a burn, for instance).
Titin
Titin is the largest known protein; its human variant consists of 34,350 amino acids, with the molecular weight of the mature "canonical" isoform of the protein being approximately 3,816,188.13 Da. Its mouse homologue is even larger, comprising 35,213 amino acids with a MW of 3,906,487.6 Da. It has a theoretical isoelectric point of 6.01. The protein's empirical chemical formula is CHNOS. It has a theoretical instability index (II) of 42.41, classifying the protein as unstable. The protein's in vivo half-life, the time it takes for half of the amount of protein in a cell to break down after its synthesis in the cell, is predicted to be approximately 30 hours (in mammalian reticulocytes).
FAM63A
In FAM63A, there are several amino acids that are conserved in all vertebrates for which sequences are available. Gly239 is the only amino acid that is conserved in all vertebrates, invertebrates, and plants for which sequences are available. Because there is only one amino acid that is absolutely conserved, a possible function for the conserved Glycine was not deduced. The 25 amino acid sequence ranging from Val313 to Gly338 is the most highly conserved in all vertebrates, invertebrates, and plants for which sequences are available. Although the sequence is not absolutely conserved, it is very highly conserved, even in the most distantly related organisms like fungi and plants.
C20orf96
The most prevalent mutations of C20orf96 in humans are M1V, Q6K, T13I, T13S, M94I, S117G, S117T, S117N, L142V, D159N, M215T, D238E, R251C, R251G, Q263E, R279C, E304G, I305F, M313I, R328W, R342I, and L353V. The format these mutations are given in are the amino acid that is supposed to be there, the amino acid number, and then the mutation.
Sports nutrition
To compensate for this glycogen reduction, athletes will often take in large amounts of carbohydrates, immediately following their exercise. Typically, high-glycemic-index carbohydrates are preferred for their ability to rapidly raise blood glucose levels.For the purpose of protein synthesis, protein or individual amino acids are ingested as well. Branched-chain amino acids are important since they are most responsible for the synthesis of protein. According to Lemon et al. (1995) female endurance runners have the hardest time getting enough protein in their diet. Endurance athletes in general need more protein in their diet than the sedentary person.Research has shown that endurance athletes are recommended to have 1.2 to 1.4 g of protein per kg of body weight in order to repair damaged tissue. If the athlete consumes too few calories for the body's needs, lean tissue will be broken down for energy and repair. Protein deficiency can cause many problems such as early and extreme fatigue, particularly long recovery, and poor wound healing. Complete proteins such as meat, eggs, and soy provide the athlete with all essential amino acids for synthesizing new tissues. However, vegetarian and vegan athletes frequently combine legumes with a whole grain to provide the body with a complete protein across the day's food intake. A popular combination being rice and beans.
Alanine
Alanine (symbol Ala or A) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated form, −NH, under biological conditions), an α-carboxylic acid group (which is in the deprotonated form, −COO, under biological conditions), and a side chain methyl group, making it a nonpolar, aliphatic amino acid. It is non-essential in humans: because the body can synthesize it, it does not need to be present in the diet. It is encoded by all codons starting with GC (GCU, GCC, GCA, and GCG).
Gynoid fat distribution
Gynoid fat is mainly composed of long-chain polyunsaturated fatty acids. It is proposed that babies which are breast-fed are more likely to have increased cognitive capabilities due to these fatty acids being present in the breast milk, as they have been suggested to aid early brain development in foetuses and newborns. The most notable fatty acids found in human breast milk are Docosahexaenoic acid and Arachidonic acid, which have been shown to play crucial roles in the healthy formation and functions of neurons.
Essential amino acid
Six other amino acids are considered conditionally essential in the human diet, meaning their synthesis can be limited under special pathophysiological conditions, such as prematurity in the infant or individuals in severe catabolic distress. These six are arginine, cysteine, glycine, glutamine, proline, and tyrosine. Six amino acids are non-essential (dispensable) in humans, meaning they can be synthesized in sufficient quantities in the body. These six are alanine, aspartic acid, asparagine, glutamic acid, serine, and selenocysteine. The amino acid, pyrrolysine, considered the 22nd one, is not used by humans; thus, it is non-essential.
Alkaline phosphatase
In humans, alkaline phosphatase is present in all tissues throughout the entire body, but is particularly concentrated in the liver, bile duct, kidney, bone, intestinal mucosa and placenta. In the serum, two types of alkaline phosphatase isozymes predominate: skeletal and liver. During childhood the majority of alkaline phosphatase are of skeletal origin. Humans and most other mammals contain the following alkaline phosphatase isozymes:
Four genes encode the four isozymes. The gene for tissue-nonspecific alkaline phosphatase is located on chromosome 1, and the genes for the other three isoforms are located on chromosome 2.
Nutrition and cognition
Foods that are rich in omega-3 fatty acids have been shown to decrease risk of getting Alzheimer's disease. Omega-3 fatty acids, primarily docosahexaenoic acid (DHA), which is the most prevalent omega-3 fatty acid found in neurons, have been studied extensively for use in possible prevention and therapy of Alzheimer's disease. Some studies (cross-sectional) suggest that reduced intake or low brain levels of DHA are associated with earlier development of cognitive deficits or development of dementia, including Alzheimer's disease. Several clinical trials suggest that omega-3 fatty acid supplementation does not have significant effects in the treatment of Alzheimer's disease—which in turn may suggest that the protective benefits of omega-3 fatty acid supplementation could depend on the scope of the disease and other confounding factors. A diet that is rich in antioxidants will also help get rid of free radicals in the body, which could be a cause for Alzheimer's. The buildup of Beta Amyloid plaques, a marker highly associated with Alzheimer's disease, generates cell damaging free radicals. Therefore, the role of antioxidants as protectants against Alzheimer's disease has become a hot topic of study. Simple dietary modification, towards fewer highly processed carbohydrates and relatively more fats ad cholesterol, is likely a protective measure against Alzheimer's disease.
Dietary supplement
Proteins are chains of amino acids. Nine of these proteinogenic amino acids are considered essential for humans because they cannot be produced from other compounds by the human body and so must be taken in as food. Recommended intakes, expressed as milligrams per kilogram of body weight per day, have been established. Other amino acids may be conditionally essential for certain ages or medical conditions. Amino acids, individually and in combinations, are sold as dietary supplements. The claim for supplementing with the branched chain amino acids leucine, valine and isoleucine is for stimulating muscle protein synthesis. A review of the literature concluded this claim was unwarranted. In elderly people, supplementation with just leucine resulted in a modest (0.99 kg) increase in lean body mass. The non-essential amino acid arginine, consumed in sufficient amounts, is thought to act as a donor for the synthesis of nitric oxide, a vasodilator. A review confirmed blood pressure lowering. Taurine, a popular dietary supplement ingredient with claims made for sports performance, is technically not an amino acid. It is synthesized in the body from the amino acid cysteine.
C16orf71
Alanine was the most abundant amino acid, contributing to 11.54% of the molecular weight of the protein. Serine was the second most abundant, contributing 10.19% to the overall molecular weight. The average Alanine frequency in vertebrate proteins is approximately 7.4% and the average Serine frequency is approximately 8.1%.
Angiotensin
Angiotensinogen is also known as renin substrate. Human angiotensinogen is 452 amino acids long, but other species have angiotensinogen of varying sizes. The first 12 amino acids are the most important for activity.
Magnesium
Magnesium is the eleventh most abundant element by mass in the human body and is essential to all cells and some 300 enzymes. Magnesium ions interact with polyphosphate compounds such as ATP, DNA, and RNA. Hundreds of enzymes require magnesium ions to function. Magnesium compounds are used medicinally as common laxatives, antacids (e.g., milk of magnesia), and to stabilize abnormal nerve excitation or blood vessel spasm in such conditions as eclampsia.
Essential amino acid
Estimating the daily requirement for the indispensable amino acids has proven to be difficult; these numbers have undergone considerable revision over the last 20 years. The following table lists the WHO and United States recommended daily amounts currently in use for essential amino acids in adult humans, together with their standard one-letter abbreviations.
Amine
An overview of the reactions of amines is given below:
Amines are ubiquitous in biology. The breakdown of amino acids releases amines, famously in the case of decaying fish which smell of trimethylamine. Many neurotransmitters are amines, including epinephrine, norepinephrine, dopamine, serotonin, and histamine. Protonated amino groups () are the most common positively charged moieties in proteins, specifically in the amino acid lysine. The anionic polymer DNA is typically bound to various amine-rich proteins. Additionally, the terminal charged primary ammonium on lysine forms salt bridges with carboxylate groups of other amino acids in polypeptides, which is one of the primary influences on the three-dimensional structures of proteins.