Glutamine
Glutamine (symbol Gln or Q) is an α-amino acid that is used in the biosynthesis of proteins. Its side chain is similar to that of glutamic acid, except the carboxylic acid group is replaced by an amide. It is classified as a charge-neutral, polar amino acid. It is non-essential and conditionally essential in humans, meaning the body can usually synthesize sufficient amounts of it, but in some instances of stress, the body's demand for glutamine increases, and glutamine must be obtained from the diet. It is encoded by the codons CAA and CAG.
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.