Peroxydisulfate anion-induced crosslinking of proteins.

Abstract

Peroxydisulfate anion in aqueous solutions is a strong oxidizing agent decomposing to sulfate free radicals and subsequently to hydroxyl radicals. In the presence of proteins, aqueous solutions of peroxydisulfate undergo more rapid induced decomposition to these free radical species, which in turn leads to oxidative attack and crosslinking and/or degradation of the protein. Under mild conditions and at low peroxydisulfate concentrations, protein crosslinking predominates over degradation. Peroxydisulfate-induced crosslinking of gelatin, fibroin, and other proteins is reviewed. The mechanism of crosslinking is interpreted in light of physical and chemical data, amino acid analyses, peroxydisulfate's known mode of decomposition, the effect of protein modification on oxidative crosslinking, and related model compound studies.