Redox characteristics of the tungsten DMSO reductase of Rhodobacter capsulatus

FEBS Letters

Bailey, Susan⁴  Hagedoorn, Peter-Leon³  Hagen, Wilfred R.³  Garner, C.David²  Docrat, Arefa¹  Stewart, Lisa J.⁴ 

[1] Department of Chemistry, Manchester University, Manchester M13 9PL, UK;School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK;Kluyver Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands;CLRC Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD, UK

关键词: Dimethylsulfoxide reductase;    Tungsten;    Molybdenum;    Midpoint potential;    Electron paramagnetic resonance;   

DOI  :  10.1016/S0014-5793(03)01359-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The dimethylsulfoxide reductase (DMSOR) from Rhodobacter capsulatus is known to retain its three-dimensional structure and enzymatic activity upon substitution of molybdenum, the metal that occurs naturally at the active site, by tungsten. The redox properties of tungsten-substituted DMSOR (W-DMSOR) have been investigated by a dye-mediated reductive titration with the concentration of the W^V state monitored by EPR spectroscopy. At pH 7.0, E _m(W^VI/W^V) is −194 mV and E _m(W^V/W^IV) is −134 mV. Each E _m value of W-DMSOR is significantly lower (220 and 334 mV, respectively) than that of the corresponding couple of Mo-DMSOR. These redox potentials are consistent with the ability of Mo-DMSOR to catalyze both the reduction of DMSO to DMS and the back reaction, whereas W-DMSOR is very effective in catalyzing the forward reaction, but shows no ability to catalyze the oxidation of DMS to DMSO.

【 授权许可】

Unknown