Possible Interaction: Cysteine and Hydrogen Peroxide

“Focusing on three ER-localized proteins—the molecular chaperone BiP, the transmembrane stress-sensor IRE1, and the calcium pump SERCA2—we discuss how post-translational modification of protein cysteines by H2O2 can alter ER activities.”

“The cysteines of most H2O2 effectors are therefore at a competitive disadvantage for reaction with H2O2.”

“PYK2 downregulation, l-cysteine supplementation, or CSE overexpression alleviated the effects of H2O2 on H9c2 cardiomyocyte survival.”

“Given that Prxs are abundant and possess a structure that renders the cysteine (Cys) residue at the active site highly sensitive to oxidation by H2O2 , the signaling function of this oxidant requires extensive and highly localized regulation.”

“Here, we report that hydrogen peroxide heightens endocannabinoid signaling in brain neurons through sulfenylation of cysteines C201 and C208 in monoacylglycerol lipase (MGL), a serine hydrolase that deactivates the endocannabinoid 2-arachidonoyl-sn-glycerol (2-AG) in nerve terminals.”

“Peroxiredoxins (Prxs) contain an active site cysteine that is sensitive to oxidation by H2O2.”

“Pretreatment with hydrogen peroxide , l‐aspartic acid β‐hydroxamate or 1‐methyl‐4‐phenylpyridinium reduced the subsequent cysteine increase in midbrain slice cultures.”

“3-Mercaptopyruvate sulfurtransferase serves as an antioxidant protein: when the enzyme is exposed to stoichiometric amounts of the oxidant hydrogen peroxide , it is inhibited via the formation of low redox sulfenate at the catalytic site cysteine.”

“This suppressive effect of H2O2 could be relieved by reducing agents (dithiothreitol and cysteine).”

“Specifically, H2O2 appears to oxidize active site cysteines in phosphatases, thereby inactivating them.”