Modeling the Catalytic Cycle of Glutathione Peroxidase by Nuclear Magnetic Resonance Spectroscopic Analysis of Selenocysteine Selenenic Acids
Ryosuke Masuda, Ryutaro Kimura, Takafumi Karasaki, Shohei Sase, Kei Goto
Abstract
Se NMR) evidence for the formation of Sec-SeOH in small-molecule selenocysteine and selenopeptide model systems with a cradle-type protective group. The catalytic cycle of GPx was investigated using NMR-observable Sec-SeOH models. All the hitherto proposed chemical processes, i.e., not only those of the canonical catalytic cycle but also those involved in the bypass mechanism, including the intramolecular cyclization of Sec-SeOH to the corresponding five-membered ring selenenyl amide, were examined in a stepwise manner.
Topics & Concepts
SelenocysteineChemistryCatalytic cycleAmideGlutathione peroxidaseCatalysisStereochemistrySmall moleculePeroxidaseIntramolecular forceGlutathioneEnzymeBiochemistryCysteineOrganoselenium and organotellurium chemistrySelenium in Biological SystemsSulfur Compounds in Biology