title: Diastereoselective reduction of protein-bound methionine sulfoxide by methionine sulfoxide reductase.
abstract: Methionine sulfoxide (MetSO) in calmodulin (CaM) was previously shown to be a substrate for bovine liver peptide methionine sulfoxide reductase (pMSR, EC 1.8.4.6), which can partially recover protein structure and function of oxidized CaM in vitro. Here, we report for the first time that pMSR selectively reduces the D-sulfoxide diastereomer of CaM-bound L-MetSO (L-Met-D-SO). After exhaustive reduction by pMSR, the ratio of L-Met-D-SO to L-Met-L-SO decreased to about 1:25 for hydrogen peroxide-oxidized CaM, and to about 1:10 for free MetSO. The accumulation of MetSO upon oxidative stress and aging in vivo may be related to incomplete, diastereoselective, repair by pMSR.
authors.affiliation: Department of Pharmaceutical Chemistry, University of Kansas, Lawrence 66047, USA.
authors.forename: V S
authors.initials: VS
authors.lastname: Sharov
authors.forename: D A
authors.initials: DA
authors.lastname: Ferrington
authors.forename: T C
authors.initials: TC
authors.lastname: Squier
authors.forename: C
authors.initials: C
authors.lastname: Schöneich
mesh_terms: D000375:Aging / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002147:Calmodulin / Q000235:genetics / Q000378:metabolism; D002417:Cattle; D066298:In Vitro Techniques; D008715:Methionine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D051150:Methionine Sulfoxide Reductases; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D002147:Calmodulin; D011994:Recombinant Proteins; D008715:Methionine; D010088:Oxidoreductases; D051150:Methionine Sulfoxide Reductases; C027219:methionine sulfoxide reductase; C013111:methionine sulfoxide