title: Reversible hydrogenase of Anabaena variabilis ATCC 29413: catalytic properties and characterization of redox centres.
abstract: The catalytic and spectroscopic properties of the reversible hydrogenase from the cyanobacterium Anabaena variabilis have been examined. The hydrogenase required reductive activation in order to elicit hydrogen-oxidation activity. Carbon monoxide was a weak (Ki=35 microM), reversible and competitive inhibitor. A flavin with the chromatographic properties of FMN, and nickel were detected in the purified enzyme. A. variabilis hydrogenase exhibited electron paramagnetic resonance (EPR) spectra in its hydrogen-reduced state, indicative of [2Fe-2S] and [4Fe-4S] clusters. Although no EPR signals due to nickel were detected, the results are consistent with the enzyme being a flavin-containing hydrogenase of the nickel-iron type.
authors.affiliation: Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
authors.forename: L T
authors.initials: LT
authors.lastname: Serebryakova
authors.forename: M
authors.initials: M
authors.lastname: Medina
authors.forename: N A
authors.initials: NA
authors.lastname: Zorin
authors.forename: I N
authors.initials: IN
authors.lastname: Gogotov
authors.forename: R
authors.initials: R
authors.lastname: Cammack
mesh_terms: D017033:Anabaena / Q000201:enzymology*; D001665:Binding Sites; D002248:Carbon Monoxide / Q000494:pharmacology; D004227:Dithionite / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005415:Flavins / Q000032:analysis; D006864:Hydrogenase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000737:chemistry; D007700:Kinetics; D009532:Nickel / Q000032:analysis; D010084:Oxidation-Reduction
chemical_list: D004791:Enzyme Inhibitors; D005415:Flavins; D007506:Iron-Sulfur Proteins; D004227:Dithionite; D009532:Nickel; D002248:Carbon Monoxide; D006864:Hydrogenase