Nitrite, a new substrate for nitrogenase

Journal Article · Tue Jan 24 04:00:00 EST 1989 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00428a002· OSTI ID:5512705

Vaughn, S A; Burgess, B K ^[1]

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1. Univ. of California, Irvine (USA)

The authors have examined the reactivity of the purified component proteins of Azotobacter vinelandii nitrogenase (Av1 and Av2) toward nitrate and nitrite. Nitrate has no effect on H{sub 2} evolution or C{sub 2}H{sub 2} reduction by nitrogenase and thus is neither a substrate nor an inhibitor. Nitrite dramatically inhibits H{sub 2} evolution. This inhibition has two components, one irreversible and one reversible upon addition of CO. The irreversible inhibition is due to nitrite inactivation of the Fe protein. The rate of this inactivation is greatly enhanced by addition of MgATP, suggesting the (4Fe-4S) cluster is the site of nitrite attack. The reversible inhibition does not represent an inhibition of electron flow but rather a diversion of electrons away from H{sub 2} evolution and into the six-electron reduction of nitrite to ammonia. Thus, nitrogenase functions as a nitrite reductase.

• OSTI ID: 5512705
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 28:2; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AZOTOBACTER
BACTERIA
BIOCHEMICAL REACTION KINETICS
BIOCHEMISTRY
BIOLOGICAL EFFECTS
CHEMISTRY
ENZYME INHIBITORS
ENZYMES
INACTIVATION
IRON COMPOUNDS
KINETICS
METALLOPROTEINS
MICROORGANISMS
MOLYBDENUM COMPOUNDS
NITRATES
NITRITES
NITRO-GROUP DEHYDROGENASES
NITROGEN COMPOUNDS
NITROGENASE
ORGANIC COMPOUNDS
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PROTEINS
REACTION KINETICS
REFRACTORY METAL COMPOUNDS
TRANSITION ELEMENT COMPOUNDS