Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
The chemical evolution of a nitrogenase model, XXIII. The nature of the active site and the role of homocitric acid in MoFe-nitrogenase
Autore:
Palmer, JG; Doemeny, PA; Schrauzer, GN;
Indirizzi:
Univ Calif San Diego, Dept Chem & Biochem, Revelle Coll, La Jolla, CA 92093 USA Univ Calif San Diego La Jolla CA USA 92093 e Coll, La Jolla, CA 92093 USA
Titolo Testata:
ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES
fascicolo: 4-5, volume: 56, anno: 2001,
pagine: 386 - 393
SICI:
0932-0776(200104/05)56:4-5<386:TCEOAN>2.0.ZU;2-J
Fonte:
ISI
Lingua:
ENG
Soggetto:
HYDROGEN-EVOLVING SYSTEMS; IRON MOLYBDENUM COFACTOR; FEMO-COFACTOR; MOLECULAR NITROGEN; ENZYMATIC REDUCTION; CLUSTER; MECHANISM; ACETYLENE; MOLYBDATE; BINDING;
Keywords:
nitrogen; acetylene; homocitric acid;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
33
Recensione:
Indirizzi per estratti:
Indirizzo: Schrauzer, GN Univ Calif San Diego, Dept Chem & Biochem, Revelle Coll, La Jolla, CA 92093 USA Univ Calif San Diego La Jolla CA USA 92093 la, CA 92093 USA
Citazione:
J.G. Palmer et al., "The chemical evolution of a nitrogenase model, XXIII. The nature of the active site and the role of homocitric acid in MoFe-nitrogenase", Z NATURFO B, 56(4-5), 2001, pp. 386-393

Abstract

The iron-molybdenum cofactor (FeMo-co) of bacterial nitrogenase is a heterometallic cluster of composition MoFe7S9 that is attached to the apoproteinby a coordinative Mo-N bond to the imidazole group of his alpha 442, and by a Fe-S bond to cys alpha 275. The molybdenum atom of FeMo-co in the enzyme in addition is coordinated to one molecule of homocitrate (hc), which is required for maximal Na reducing activity. The molybdenum atom in the enzyme-bound FeMo-co thus is hexacoordinated and cannot react with substrates unless free coordination sites are made available. It is proposed that the reactions of the substrates of nitrogenase occur at a molybdenum active site consisting of a mononuclear molybdenum homocitrate complex attached to his alpha 442 of the apoprotein that in the functional enzyme is generated fromFeMo-co by a reversible, redox-linked dissociation of the Fe7S9-cys cluster. Studies with catalytic model systems consisting of complexes of molybdenum with imidazole and hydroxo-carboxylate ligands support this proposal andprovide a rationale for the specific activating effect of homocitrate in nitrogenase.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 10/07/20 alle ore 15:58:49