Protein thioacylation. 1. Reagents design and synthesis

Thioacylation is a new way for protein chemical modification. Carboxylic dithioesters and -acids react selectively and rapidly at room temperature with aliphatic amines such as lysine epsilon-amino groups leading to thioamide formation, without any other reagent or catalyst. Various thioacylating reagents were synthesized: monofunctional dithioesters bearing on the acylating end various chemical groups such as: aliphatic chains, phenyl group, mono- and dicarboxylic acids, dialkylphosphonic ester, phosphonic acid, thiol, phenol, or quaternary ammonium group. Bifunctional dithioesters containing either a polymethylene chain or an ethylene oxide oligomer as spacer group as well as some mono- and bis(dithio acids) are described. Applications of thioacylation may be involved either in enzyme chemical modifications or in the obtention of new materials from proteins. Bifunctional reagents might be used as cross-linking or coupling reagents.