Oxidative modification of methionine80 in cytochrome c by reaction with peroxides

Lysine carbonylation is a previously unrecognized contributor to peroxidase activation of cytochrome c by chloramine-T

“…S1†). 17,37,46,47 No other +16 Da modifications were detected. These observations appear to support the widely held belief that CT selectively oxidizes Met 17,48,50,51.…”

Determination of proton concentration at cardiolipin-containing membrane interfaces and its relation with the peroxidase activity of cytochromec

“…6C and D, and Table 2), indicating that other factors than the interface pH′ affect the peroxidase activity of cyt c . Related to this, protein modification of cyt c may also affect its peroxidase activity 41…”

New Aspects of Cytochrome c: 3D Domain Swapping, Membrane Interaction, Peroxidase Activity, and Met80 Sulfoxide Modification

“…117 To understand the peroxidase reaction of cyt c in more detail, we investigated the reaction mechanism of Met80 sulfoxide modification and the effect of Met80 sulfoxidation on peroxidase activity. 118,119 Cyt c interacts electrostatically with zwitterionic lipids 1,2-dioleoyl-sn-glycero-3phosphocholine (DOPC) and 1,2-distearoyl-sn-glycero-3phosphatidylethanolamine (DSPE) through the mediation of phosphate anions and reacts efficiently with H 2 O 2 , selectively oxidizing the sulfur atom of the axial ligand Met80. 120 Met80 is oxidized to Met sulfoxide for ferric cyt c by the reaction of the heme with H 2 O 2 or mCPBA in the presence of CLcontaining liposomes through the formation of a Compound I species.…”

“…120 Met80 is oxidized to Met sulfoxide for ferric cyt c by the reaction of the heme with H 2 O 2 or mCPBA in the presence of CLcontaining liposomes through the formation of a Compound I species. 119,121 After the reaction of cyt c with mCPBA in the presence of DOPC liposomes containing CL, the electrospray ionization mass spectrum of the peptide fragments®obtained by digestion of cyt c with lysyl endopeptidase®exhibits a peak at m/z = 795.45; whereas, this peak is not observed for the peptide fragments obtained after the reaction in the presence of DOPC liposomes not containing CL. According to the tandem mass spectrum of the m/z = 795.45 peptide fragment, Met80 is modified with a 16 Da mass increase.…”