title: Purification and characterization of pyruvate: ferredoxin oxidoreductase from the anaerobic protozoon Trichomonas vaginalis.
abstract: The pyruvate: ferredoxin oxidoreductase from the anaerobic protozoon Trichomonas vaginalis is an extrinsic protein bound to the hydrogenosomal membrane. It has been solubilized and purified to homogeneity, principally by salting-out chromatography on Sepharose 4B. Low recoveries of active enzyme were caused by inactivation by O2 and the irreversible loss of thiamin pyrophosphate. It is a dimeric enzyme of overall Mr 240,000 and subunit Mr 120,000. The enzyme contains, per mol of dimer, 7.3 +/- 0.3 mol of iron and 5.9 +/- 0.9 mol of acid-labile sulphur, suggesting the presence of two [4Fe-4S] centres, and 0.47 mol of thiamin pyrophosphate. The absorption spectrum of the enzyme is characteristic of a non-haem iron protein. The pyruvate: ferredoxin oxidoreductase from T. vaginalis is therefore broadly similar to the 2-oxo acid: ferredoxin (flavodoxin) oxidoreductases purified from bacterial sources, except that it is membrane-bound.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D005288:Ferredoxins / Q000378:metabolism; D007658:Ketone Oxidoreductases / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D050743:Pyruvate Synthase; D013053:Spectrophotometry; D014246:Trichomonas vaginalis / Q000201:enzymology*; D014755:Viologens / Q000378:metabolism
chemical_list: D000596:Amino Acids; D005288:Ferredoxins; D014755:Viologens; D007658:Ketone Oxidoreductases; D050743:Pyruvate Synthase