Oxygen effects on the nickel- and iron-containing hydrogenase from Azotobacter vinelandii

The effects of O sub(2) on membrane-bound Azotobacter vinelandii) hydrogenase in both the membrane-associated and purified states were characterized. O sub(2) was a rapid-equilibrium, reversible inhibitor both of H sub(2) oxidation/electron acceptor reduction activity and of the exchange activity. O...

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Bibliographic Details
Published in:Biochemistry (Easton) 1989-02, Vol.28 (4), p.1588-1596
Main Authors: Seefeldt, Lance C, Arp, Daniel J
Format: Article
Language:English
Subjects:
550201 - Biochemistry- Tracer Techniques
ACTIVIDAD ENZIMATICA
ACTIVITE ENZYMATIQUE
AZOTOBACTER
Azotobacter vinelandii
BACTERIA
BASIC BIOLOGICAL SCIENCES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CELL CONSTITUENTS
CELL MEMBRANES
CHALCOGENIDES
ELEMENTS
ENZYME INHIBITORS
ENZYMES
ENZYMIC ACTIVITY
FER
HIERRO
HYDROGEN COMPOUNDS
hydrogenase
HYDROGENASES
INACTIVATION
IRON
IRON COMPOUNDS
KINETICS
MEMBRANES
MICROORGANISMS
NICKEL
NICKEL COMPOUNDS
NIQUEL
NONMETALS
OXIDES
OXIDOREDUCTASES
OXIGENO
OXYGEN
OXYGEN COMPOUNDS
OXYGENE
REACTION KINETICS
TRANSITION ELEMENT COMPOUNDS
TRITIUM COMPOUNDS
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Summary:The effects of O sub(2) on membrane-bound Azotobacter vinelandii) hydrogenase in both the membrane-associated and purified states were characterized. O sub(2) was a rapid-equilibrium, reversible inhibitor both of H sub(2) oxidation/electron acceptor reduction activity and of the exchange activity. O sub(2) inhibition was noncompetitive versus the electron acceptor methylene blue and uncompetitive versus the substrate H sub(2). This is the first report of H sub(2) protection from O sub(2)-dependent, irreversible inactivation for any hydrogenase. The competitive inhibitor CO did not affect the irreversible inactivation by O sub(2) or the protection by H sub(2). A model is proposed that outlines various oxidation states of this hydrogenase and the effects of O sub(2) on each state.
ISSN:0006-2960
1520-4995
DOI:10.1021/bi00430a025