3+] can suppress vascular NO production in endothelial cells. Abnormal vessels can cause obstruction by either encircling the trachea and esophagus (complete vascular ring) or compressing the anterior wall of the trachea alone.
Î±-Amino acid (alpha-amino acid): A molecule containing an amino group and a carboxylic acid group that are separated by one carbon, called the Î±-carbon. In biochemistry there are twenty standard amino acids which differ in the makeup of the side chain (R group) attached to the Î±-carbon.-Amino acid (alpha-amino acid): A molecule containing an amino group and a carboxylic acid group that are separated by one carbon, called the Î±-carbon. In biochemistry there are twenty standard amino acids which differ in the makeup of the side chain (R group) attached to the Î±-carbon.
The alpha helix (Î±-helix) is a common secondary structure of proteins and is a righthand-coiled or spiral conformation (helix) in which every backbone N-H group donates a hydrogen bond to the backbone C=O group of the amino acid four residues earlier (hydrogen bonding).ifferent amino-acid sequences have different propensities for forming Î±-helical structure. Methionine, alanine, leucine uncharged, glutamate, and lysine (MALEK in the amino-acid 1-letter codes) all have especially high helix-forming propensities, whereas proline and glycine have poor helix-forming propensities.