Lysine is an α-amino acid that is a precursor of many proteins. It contains an α-amino group (located on the protonated −NH+
3 form), the α-carboxylic acid group (deprotonated -COO- form under biological conditions) and the side chain lysyl ((CH2)4NH2), classifying it as basic, charged (under physiological conditions lower pH), aliphatic amino acids. It is encoded by the codons AAA and AAG. Like almost all other amino acids, the alpha-carbon is chiral, and lysine can refer to an enantiomer or a racemic mixture of the two. For the purposes of this document, lysine refers to the biologically active enantiomer L-lysine, in which the α-carbon is in the S configuration.
The human body cannot synthesize lysine. It is essential to humans and therefore must be obtained from the diet. In organisms that synthesize lysine, there are two main biosynthetic pathways, the diaminopimelate and the α-aminoadipic acid pathways, which use different enzymes and substrates and are present in a variety of organisms . Lysine catabolism occurs through one of several pathways, the most common of which is the saccharin pathway.
Lysine plays multiple roles in humans, most importantly in proteinogenesis, but also in the cross-linking of collagen peptides, the uptake of essential mineral nutrients, and the production of carnitine, which is involved in the metabolism of fatty acids The essential. Lysine is also frequently involved in histone modifications, thereby affecting the epigenome. The ε-amino group is frequently involved in hydrogen bonding and acts as a universal base in catalysis. ε-ammonium group (−NH+
3) The fourth carbon attached to the α-carbon, which is attached to a carboxyl (C=OOH) group. [3]
Due to the importance of lysine in a variety of biological processes, lysine deficiency can lead to a variety of disease states, including connective tissue defects, impaired fatty acid metabolism, anemia, and systemic protein energy deficiency. Conversely, excess lysine resulting from ineffective catabolism can lead to serious neurological disorders.
