Tetrasodium pyrophosphate ameliorates oxidative damage to the TGase-catalyzed gelation of actomyosins

Abstract

The present study attempted to investigate the interactive roles of protein oxidation (0–20 mM H2O2) and tetrasodium pyrophosphate (TSPP) on the crosslinking efficiency of actomyosin mediated by transglutaminase (TGase). Oxidation at 0–20 mM H2O2 was not conducive to TGase-mediated crosslinking as indicated by the relative reduction of free amine consumption from 35.3% to 11.7%, and caused the principle crosslinking sites to progressively convert from myosin subfragment-1 (S1) to subfragment-1 (S2) as evidenced by electrophoresis. However, the binding of TSPP to myosin alleviated oxidation suppression to TGase-catalyzed crosslinking in varying degrees and retarded the migration of crosslinking site from S1 to S2. Moreover, oxidation (especially 20 mM H2O2) decreased the final (90 °C) elasticity index (EI) and water holding capacity of TGase-treated actomyosin gel, while TSPP intensified those of TGase-catalyzed actomyosin gel, indicating that TSPP had a positive effect on ameliorating the oxidative stress to TGase-catalyzed gelation of actomyosin.