Purification and characterization of a tungsten-containing formate dehydrogenase from Desulfovibrio gigas

Citation
Mj. Almendra et al., Purification and characterization of a tungsten-containing formate dehydrogenase from Desulfovibrio gigas, BIOCHEM, 38(49), 1999, pp. 16366-16372
Citations number
30
Categorie Soggetti
Biochemistry & Biophysics
Journal title
BIOCHEMISTRY
ISSN journal
00062960 → ACNP
Volume
38
Issue
49
Year of publication
1999
Pages
16366 - 16372
Database
ISI
SICI code
0006-2960(199912)38:49<16366:PACOAT>2.0.ZU;2-B
Abstract
An air-stable formate dehydrogenase (FDH), an enzyme that catalyzes the oxi dation of formate to carbon dioxide, was purified from the sulfate reducing organism Desulfovibrio gigas (D. gigas) NCIB 9332. D. gigas FDH is a heter odimeric protein [alpha (92 kDa) and beta (29 kDa) subunits] and contains 7 +/- 1 Fe/protein and 0.9 +/- 0.1 W/protein, Selenium was not detected. The UV/visible absorption spectrum of D, gigas FDH is typical of an iron-sulfu r protein. Analysis of pterin nucleotides yielded a content of 1.3 +/- 0.1 guanine monophosphate/mol of enzyme, which suggests a tungsten coordination with two molybdopterin guanine dinucleotide cofactors. Both Mossbauer spec troscopy performed on D. gigas FDH grown in a medium enriched with Fe-57 an d EPR studies performed in the native and fully reduced state of the protei n confirmed the presence of two [4Fe-4S] clusters. Variable-temperature EPR studies showed the presence of two signals compatible with an atom in a d( 1) configuration albeit with an unusual relaxation behavior as compared to the one generally observed for W(V) ions.