L-Lysine

L-Lysine (CAS No.: 56-87-1) is a naturally occurring basic α-amino acid classified among the essential amino acids and widely utilized in biochemical and biomedical research as a model substrate for studying amino acid metabolism, protein structure, and post-translational modification processes. Encoded by conserved codons and characterized by a reactive ε-amino group, lysine serves as a key site for enzymatic modifications including methylation, acetylation, hydroxylation, and glycosylation, thereby playing a central role in epigenetic regulation, protein–protein interactions, and intracellular signaling pathways. Lysine residues are critical in histone modification dynamics and are involved in regulating chromatin structure and gene expression, making this compound highly relevant for studies of transcriptional control and cellular differentiation. In addition, lysine participates in mechanisms associated with amino acid transport and competitive interactions with arginine, which has been exploited in experimental models investigating viral replication and host–pathogen interactions, particularly in herpes simplex virus systems. In vitro studies typically employ lysine in concentrations ranging from low micromolar to millimolar levels depending on the assay system, with applications spanning cell culture supplementation, metabolic flux analysis, and enzyme activity assays. Furthermore, lysine is frequently used in animal and cellular models to investigate pathways related to nutrient sensing, inflammation, and protein turnover, with experimental dosing tailored to specific study designs and endpoints.