@article {2380,
	title = {Incorporation of either molybdenum or tungsten into formate dehydrogenase from Desulfovibrio alaskensis NCIMB 13491; EPR assignment of the proximal iron-sulfur cluster to the pterin cofactor in formate dehydrogenases from sulfate-reducing bacteria},
	journal = {J Biol Inorg Chem},
	volume = {9},
	number = {2},
	year = {2004},
	note = {<p>0949-8257 (Print)0949-8257 (Linking)Journal ArticleResearch Support, Non-U.S. Gov{\textquoteright}t</p>
},
	month = {Mar},
	pages = {145-51},
	abstract = {<p>We report the characterization of the molecular properties and EPR studies of a new formate dehydrogenase (FDH) from the sulfate-reducing organism Desulfovibrio alaskensis NCIMB 13491. FDHs are enzymes that catalyze the two-electron oxidation of formate to carbon dioxide in several aerobic and anaerobic organisms. D. alaskensis FDH is a heterodimeric protein with a molecular weight of 126+/-2 kDa composed of two subunits, alpha=93+/-3 kDa and beta=32+/-2 kDa, which contains 6+/-1 Fe/molecule, 0.4+/-0.1 Mo/molecule, 0.3+/-0.1 W/molecule, and 1.3+/-0.1 guanine monophosphate nucleotides. The UV-vis absorption spectrum of D. alaskensis FDH is typical of an iron-sulfur protein with a broad band around 400 nm. Variable-temperature EPR studies performed on reduced samples of D. alaskensis FDH showed the presence of signals associated with the different paramagnetic centers of D. alaskensis FDH. Three rhombic signals having g-values and relaxation behavior characteristic of [4Fe-4S] clusters were observed in the 5-40 K temperature range. Two EPR signals with all the g-values less than two, which accounted for less than 0.1 spin/protein, typical of mononuclear Mo(V) and W(V), respectively, were observed. The signal associated with the W(V) ion has a larger deviation from the free electron g-value, as expected for tungsten in a d(1) configuration, albeit with an unusual relaxation behavior. The EPR parameters of the Mo(V) signal are within the range of values typically found for the slow-type signal observed in several Mo-containing proteins belonging to the xanthine oxidase family of enzymes. Mo(V) resonances are split at temperatures below 50 K by magnetic coupling with one of the Fe/S clusters. The analysis of the inter-center magnetic interaction allowed us to assign the EPR-distinguishable iron-sulfur clusters with those seen in the crystal structure of a homologous enzyme.</p>
},
	keywords = {Chromatography, Gel, Chromatography, High Pressure Liquid, Desulfovibrio/chemistry/*enzymology/growth \& development, Electromagnetic Fields, Electron Spin Resonance Spectroscopy, Electrophoresis, Polyacrylamide Gel, Formate Dehydrogenases/chemistry/*metabolism, Iron/*chemistry, Molecular Weight, Molybdenum/*metabolism, Oxidation-Reduction, Pterins/*chemistry, Spectrophotometry, Ultraviolet, Sulfates/metabolism, Sulfur/*chemistry, Tungsten/*metabolism},
	url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=14669076 },
	author = {Brondino, C. D. and Passeggi, M. C. and Caldeira, J. and Almendra, M. J. and Feio, M. J. and Moura, J. J. and Moura, I.}
}
