Thioredoxin as a reducing agent for mammalian methionine sulfoxide reductases B lacking resolving cysteine.
Previous reports described thioredoxin (Trx) as a very poor reductant for mammalian MsrB2 and MsrB3, which lack a resolving Cys residue. In contrast, we here report that Trx could reduce both MsrB2 and MsrB3 enzymes, similarly to the reduction of mammalian MsrA. We demonstrated that functional Trx is required for the reduction of these enzymes. We further identified MsrB2- or MsrB3-Trx complexes formed through intermolecular disulfide bonds involving catalytic residue of Trx. The present study provides evidence that the sulfenic acid intermediate of oxidized MsrBs lacking resolving Cys could interact with Trx and be directly reduced by this protein.
Kim
Hwa-Young
HY
Department of Biochemistry and Molecular Biology, Aging-associated Vascular Disease Research Center, Yeungnam University College of Medicine, 317-1 Daemyung-dong, Namgu, Daegu 705-717, Republic of Korea. hykim@ynu.ac.kr
Kim
Jae-Ryong
JR
D000818:Animals; D003545:Cysteine / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D051150:Methionine Sulfoxide Reductases; D051379:Mice; D008840:Microfilament Proteins; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry* / Q000235:genetics; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000737:chemistry* / Q000235:genetics; D051381:Rats; D019163:Reducing Agents / Q000737:chemistry*; D013434:Sulfenic Acids / Q000737:chemistry; D013879:Thioredoxins / Q000737:chemistry* / Q000235:genetics
D008840:Microfilament Proteins; D019163:Reducing Agents; D013434:Sulfenic Acids; C516113:Txn2 protein, rat; D013879:Thioredoxins; D010088:Oxidoreductases; D050862:Oxidoreductases Acting on Sulfur Group Donors; D051150:Methionine Sulfoxide Reductases; C520510:Msrb2 protein, mouse; C027219:methionine sulfoxide reductase; C524352:MSRB3 protein, human; D003545:Cysteine