title: Alterations in mitochondrial and cytosolic methionine sulfoxide reductase activity during cardiac ischemia and reperfusion.
abstract: During cardiac ischemia/reperfusion, proteins are targets of reactive oxygen species produced by the mitochondrial respiratory chain resulting in the accumulation of oxidatively modified protein. Sulfur-containing amino acids are among the most sensitive to oxidation. Certain cysteine and methionine oxidation products can be reversed back to their reduced form within proteins by specific repair enzymes. Oxidation of methionine in protein produces methionine-S-sulfoxide and methionine-R-sulfoxide that can be catalytically reduced by two stereospecific enzymes, methionine sulfoxide reductases A and B, respectively. Due to the importance of the methionine sulfoxide reductase system in the maintenance of protein structure and function during conditions of oxidative stress, the fate of this system during ischemia/reperfusion was investigated. Mitochondrial and cytosolic methionine sulfoxide reductase activities are decreased during ischemia and at early times of reperfusion, respectively. Partial recovery of enzyme activity was observed upon extended periods of reperfusion. Evidence indicates that loss in activity is not due to a decrease in the level of MsrA but may involve structural modification of the enzyme.
authors: Laboratoire de Biologie et Biochimie Cellulaire du Vieillissement, EA 3106/IFR 117, Université Paris 7-Denis Diderot, 2 place Jussieu, Tour 33-23, 1er étage, CC 7128, 75251 Paris Cedex 05, France.
authors: Cédric R
authors: CR
authors: Picot
authors: Martine
authors: M
authors: Perichon
authors: Kathleen C
authors: KC
authors: Lundberg
authors: Bertrand
authors: B
authors: Friguet
authors: Luke I
authors: LI
authors: Szweda
authors: Isabelle
authors: I
authors: Petropoulos