Lysine residue (K)

A lysine residue is an amino acid side chain present in proteins, distinguished by its ε-amino group. Lysine residues are essential for protein structure, stability, and function. They are the primary sites for diverse and biologically crucial post-translational modifications, such as acetylation, methylation, ubiquitination, and sumoylation, especially in the histone tails that regulate chromatin structure and gene expression. Lysines also frequently appear in enzyme active sites and play structural roles in binding and catalysis. Because they are ubiquitous and numerous in proteins, targeting specifically a lysine residue (as opposed to a distinct protein or receptor) is not usually considered a therapeutic strategy, although certain drugs are designed to covalently react with lysines at functional sites on specific proteins[1][6].

Other names

Lysε-amino group of lysineproteinogenic lysine

Covalent modification of lysine preventing functional protein interactions. Inhibition or enhancement of lysine post-translational modifications (e.g., acetylation, methylation) for epigenetic drugs.