Abstract:

 Oxidative modification of cytochrome c (Cyt c) may influence the local conformation of the protein, yet the mechanism by which structural alterations of Cyt c affect its degree of oxidative modification remains unclear. In this study, Girard’s reagent T (GRT) was employed as a nuclear magnetic resonance (NMR) probe to investigate the oxidative modification levels of human Cyt c under varying environmental conditions. Experimental results demonstrated that protecting lysine residues through reductive methylation effectively reduced protein oxidation. Partial unfolding of Cyt c was found to enhance its oxidative modification, while binding with cardiolipin significantly increased the extent of oxidation. Additionally, other factors such as protein aggregation exhibited inhibitory effects on oxidative modification.

Key words: cytochrome c, oxidative modification, Girard’s reagent T, methylation, NMR