%0 Journal Article %J Eur J Biochem %D 1992 %T Mossbauer study of the native, reduced and substrate-reacted Desulfovibrio gigas aldehyde oxido-reductase %A Barata, B. A. %A Liang, J. %A Moura, I. %A Legall, J. %A Moura, J. J. %A Huynh, B. H. %K Aldehyde Oxidoreductases/*chemistry %K Desulfovibrio/*enzymology %K Dithionite/chemistry %K Electron Spin Resonance Spectroscopy %K Iron/analysis %K Molybdenum/analysis %K Oxidation-Reduction %K Spectroscopy, Mossbauer %K Substrate Specificity %M 1311679 %P 773-8 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1311679 %V 204 %X

The Desulfovibrio gigas aldehyde-oxido-reductase contains molybdenum and iron-sulfur clusters. Mossbauer spectroscopy was used to characterize the iron-sulfur clusters. Spectra of the enzyme in its oxidized, partially reduced and benzaldehyde-reacted states were recorded at different temperatures and applied magnetic fields. All the iron atoms in D. gigas aldehyde oxido-reductase are organized as [2Fe-2S] clusters. In the oxidized enzyme, the clusters are diamagnetic and exhibit a single quadrupole doublet with parameters (delta EQ = 0.62 +/- 0.02 mm/s and delta = 0.27 +/- 0.01 mm/s) typical for the [2Fe-2S]2+ state. Mossbauer spectra of the reduced clusters also show the characteristics of a [2Fe-2S]1+ cluster and can be explained by a spin-coupling model proposed for the [2Fe-2S] cluster where a high-spin ferrous ion (S = 2) is antiferromagnetically coupled to a high-spin ferric ion (S = 5/2) to form a S = 1/2 system. Two ferrous sites with different delta EQ values (3.42 mm/s and 2.93 mm/s at 85 K) are observed for the reduced enzyme, indicating the presence of two types of [2Fe-2S] clusters in the D. gigas enzyme. Taking this observation together with the re-evaluated value of iron content (3.5 +/- 0.1 Fe/molecule), it is concluded that, similar to other Mo-hydroxylases, the D. gigas aldehyde oxido-reductase also contains two spectroscopically distinguishable [2Fe-2S] clusters.

%Z

0014-2956 (Print)0014-2956 (Linking)Journal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

%8 Mar 1