Glutaredoxin serves as a reductant for methionine sulfoxide reductases with or without resolving cysteine.
Methionine sulfoxide reductases A and B (MsrA and MsrB) have been known to be thioredoxin (Trx)-dependent enzymes that catalyze the reduction of methionine sulfoxide in a stereospecific manner. This work reports that glutaredoxin, another major thiol-disulfide oxidoreductase, can serve as a reductant for both MsrA and MsrB. Glutaredoxins efficiently reduced 1-Cys MsrA lacking a resolving Cys, which is not reducible by Trx. Glutaredoxins also reduced 3-Cys MsrA containing two resolving Cys. The glutaredoxin-dependent activity of the 3-Cys MsrA was comparable with the Trx-dependent activity. The kinetic data suggest that 1-Cys MsrA is more efficiently reduced by glutaredoxin than 3-Cys form. Also, glutaredoxins could function as a reductant for 1-Cys MsrB lacking a resolving Cys as previously reported. In contrast to the previous report, 2-Cys MsrB containing a resolving Cys was reducible by the glutaredoxins. Collectively, this study demonstrates that glutaredoxins reduce MsrAs and MsrBs with or without resolving Cys.
Department of Biochemistry and Molecular Biology, Yeungnam University College of Medicine, Daegu, Republic of Korea. hykim@ynu.ac.kr
Hwa-Young
HY
Kim
D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D003013:Clostridium / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism*; D054477:Glutaredoxins / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D051150:Methionine Sulfoxide Reductases / Q000378:metabolism*; D051379:Mice; D008840:Microfilament Proteins; D010084:Oxidation-Reduction; D019163:Reducing Agents / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism
D001426:Bacterial Proteins; D054477:Glutaredoxins; D008840:Microfilament Proteins; D019163:Reducing Agents; D014157:Transcription Factors; C120376:MSRB2 protein, human; D051150:Methionine Sulfoxide Reductases; C027219:methionine sulfoxide reductase; D003545:Cysteine