L-lysine contains basic side chain and is hydrophilic in nature. The N-butyl amino group in the side chain is found to be protonated at physiological pH. Upon degradation, L-lysine gives ketone bodies. Transamination of lysine with α-ketoglutarate produces acetoacetyl CoA. L-lysine serves as a precursor for secondary metabolites, such as β-lactam antibiotics. It also serves as a precursor for the biosynthesis of α-aminoadipic acid.



L-Lysine is an essential proteinogenic α amino acid used in a wide range of applications. It has been used:
• as a supplement in cell culture media
• as a substrate for enzymes such as L-lysine oxidase (EC
• as a component of poly-lysine polymers
• as a substrate for oxidation and glycation mechanism studies
• in the preparation of cobaltous lysine