Thermodynamic Characterization of the Redox Centers within Dimethylsulfide Dehydrogenase

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• 作者：Nicole L. Creevey ; Alastair G. McEwan ; Graeme R. Hanson ; Paul V. Bernhardt
• 刊名：Biochemistry
• 出版年：2008
• 出版时间：March 25, 2008
• 年：2008
• 卷：47
• 期：12
• 页码：3770 - 3776
• 全文大小：1146K
• 年卷期：v.47,no.12(March 25, 2008)
• ISSN：1520-4995

文摘

Dimethylsulfide (DMS) dehydrogenase is a complex heterotrimeric enzyme that catalyzes the oxidation of DMS to DMSO and allows Rhodovulum sulfidophilum to grow under photolithotrophic conditions with DMS as the electron donor. The enzyme is a 164 kDa heterotrimer composed of an α-subunit that binds a bis(molybdopterin guanine dinucleotide)Mo cofactor, a polyferredoxin β-subunit, and a γ-subunit that contains a b-type heme. In this study, we describe the thermodynamic characterization of the redox centers within DMS dehydrogenase using EPR- and UV−visible-monitored potentiometry. Our results are compared with those of other bacterial Mo enzymes such as NarGHI nitrate reductase, selenate reductase, and ethylbenzene dehydrogenase. A remarkable similarity in the redox potentials of all Fe−S clusters is apparent.