Homocysteine thiolactone forms covalent adduct with arginine and histidine

Available evidences suggest that homocysteine thiolactone is solely responsible for the protein N-homocysteinylation (a process in which HTL covalently modifies the targeted protein) which is responsible for the inactivation, aggregation and precipitation of proteins on target. Previous data of MS and MS/MS has already suggested the fact that HTL reacts with the side-chain ɛ-amino group of lysine residues. Spectroscopic and chromatographic analyses revealed that side-chain amino group of arginine and histidine could also prove to be potential targets for Hcy-thiolactone.