title: Purification and characterization of methionine sulfoxide reductases from mouse and Staphylococcus aureus and their substrate stereospecificity.
abstract: Many organisms have been shown to possess a methionine sulfoxide reductase (MsrA), exhibiting high specificity for reduction the S form of free and protein-bound methionine sulfoxide to methionine. Recently, a different form of the reductase (referred to as MsrB) has been detected in several organisms. We show here that MsrB is a selenoprotein that exhibits high specificity for reduction of the R forms of free and protein-bound methionine sulfoxide. The enzyme was partially purified from mouse liver and a derivative of the mouse MsrB gene, in which the codon specifying selenocystein incorporation was replaced by the cystein codon, was prepared, cloned, and overexpressed in Escherichia coli. The properties of the modified MsrB protein were compared directly with those of MsrA. Also, we have shown that in Staphylococcus aureus there are two MsrA and one nonselenoprotein MsrB, which demonstrates the same substrate stereospecificity as the mouse MsrB.
authors.affiliation: Laboratory of Biochemistry, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA. moskivij@nhlbi.nih.gov
authors.forename: Jackob
authors.initials: J
authors.lastname: Moskovitz
authors.forename: Vineet K
authors.initials: VK
authors.lastname: Singh
authors.forename: Jesus
authors.initials: J
authors.lastname: Requena
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Wilkinson
authors.forename: Radheshyam K
authors.initials: RK
authors.lastname: Jayaswal
authors.forename: Earl R
authors.initials: ER
authors.lastname: Stadtman
mesh_terms: D000818:Animals; D003062:Codon; D003545:Cysteine / Q000737:chemistry; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism; D005609:Free Radicals; D008099:Liver / Q000201:enzymology; D008715:Methionine / Q000378:metabolism; D051150:Methionine Sulfoxide Reductases; D051379:Mice; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D010100:Oxygen / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013211:Staphylococcus aureus / Q000201:enzymology*; D013237:Stereoisomerism; D013379:Substrate Specificity; D014018:Tissue Distribution
chemical_list: D003062:Codon; D005609:Free Radicals; D011994:Recombinant Proteins; D008715:Methionine; D010088:Oxidoreductases; D051150:Methionine Sulfoxide Reductases; C027219:methionine sulfoxide reductase; D003545:Cysteine; D010100:Oxygen