Reduction of methionine selenoxide to selenomethionine by glutathione.
Selenomethionine, an amino acid occurring in proteins in place of methionine, reacts efficiently with oxidants, e.g., peroxynitrite, a biological oxidant generated in inflammatory states, to produce the oxidation product, methionine selenoxide. The present work describes the rapid and efficient reduction of the selenoxide to selenomethionine by glutathione in a stoichiometric reaction utilizing two equivalents of thiol. This nonenzymatic reaction establishes a defense line against peroxynitrite or other oxidants by selenomethionine residues in proteins, maintained by the ubiquitous thiol, glutathione.
Assmann
A
A
Institut für Physiologische Chemie I, Heinrich-Heine-Universität Düsseldorf, Germany.
Briviba
K
K
Sies
H
H
D005978:Glutathione / Q000378:metabolism*; D016566:Organoselenium Compounds / Q000378:metabolism*; D010087:Oxides / Q000378:metabolism*; D012645:Selenomethionine / Q000378:metabolism*
D016566:Organoselenium Compounds; D010087:Oxides; D012645:Selenomethionine; D005978:Glutathione