» Articles » PMID: 336036

Kinetics of Nitrogenase of Klebsiella Pneumoniae. Heterotropic Interactions Between Magnesium-adenosine 5'-diphosphate and Magnesium-adenosine 5'-triphosphate

Overview
Journal Biochem J
Specialty Biochemistry
Date 1977 Aug 1
PMID 336036
Citations 11
Authors
Affiliations
Soon will be listed here.
Abstract

The effects of MgADP and MgATP on the kinetics of a pre-steady-state electron-transfer reaction and on the steady-state kinetics of H2 evulution for nitrogenase proteins of K. pneumoniae were studied. MgADP was a competitive inhibitor of MgATP in the MgATP-induced electron transfer from the Fe-protein to the Mo-Fe-protein. A dissociation constant K'i = 20 micron was determined for MgADP. The release of MgADP or a coupled conformation change in the Fe-protein of K.pneumoniae occurred with a rate comparable with that of electron transfer, k approximately 2 X 10(2)S-1. Neither homotropic nor heterotropic interactions involving MgATP and MgADP were observed for this reaction. Steady-state kinetic data for H2 evolution exhibited heterotropic effects between MgADP and MgATP. The data have been fitted to symmetry and sequential-type models involving conformation changes in two identical subunits. The data suggest that the enzyme can bind up to molecules of either MgATP or MgADP, but is unable to bind both nucleotides simultaneously. The control of H2 evolution by the MgATP/MgADP ratio is not at the level of electron transfer between the Fe- and Mo-Fe-proteins.

Citing Articles

Electron Transfer in Nitrogenase.

Rutledge H, Tezcan F Chem Rev. 2020; 120(12):5158-5193.

PMID: 31999100 PMC: 7466952. DOI: 10.1021/acs.chemrev.9b00663.


MgATP-independent hydrogen evolution catalysed by nitrogenase: an explanation for the missing electron(s) in the MgADP-AlF4 transition-state complex.

Yousafzai F, Eady R Biochem J. 1999; 339 ( Pt 3):511-5.

PMID: 10215587 PMC: 1220184.


Respiratory control determines respiration and nitrogenase activity of Rhizobium leguminosarum bacteroids.

Haaker H, Szafran M, Wassink H, Klerk H, Appels M J Bacteriol. 1996; 178(15):4555-62.

PMID: 8755884 PMC: 178223. DOI: 10.1128/jb.178.15.4555-4562.1996.


The mechanism of Klebsiella pneumoniae nitrogenase action. Simulation of the dependences of H2-evolution rate on component-protein concentration and ratio and sodium dithionite concentration.

Thorneley R, Lowe D Biochem J. 1984; 224(3):903-9.

PMID: 6395864 PMC: 1144527. DOI: 10.1042/bj2240903.


Nitrogenase of Klebsiella pneumoniae. Kinetic studies on the Fe protein involving reduction by sodium dithionite, the binding of MgADP and a conformation change that alters the reactivity of the 4Fe-4S centre.

Ashby G, Thorneley R Biochem J. 1987; 246(2):455-65.

PMID: 3318808 PMC: 1148296. DOI: 10.1042/bj2460455.


References
1.
Ljones T . Nitrogenase from Clostridium pasteurianum. Changes in optical absorption spectra during electron transfer and effects of ATP, inhibitors and alternative substrates. Biochim Biophys Acta. 1973; 321(1):103-13. DOI: 10.1016/0005-2744(73)90064-8. View

2.
Yoch D . Electron transport carriers involved in nitrogen fixation by the coliform, Klebsiella pneumoniae. J Gen Microbiol. 1974; 83(0):153-64. DOI: 10.1099/00221287-83-1-153. View

3.
Smith B, Thorneley R, Eady R, Mortenson L . Nitrogenases from Klebsiella pneumoniae and Clostridium pasteurianum. Kinetic investigations of cross-reactions as a probe of the enzyme mechanism. Biochem J. 1976; 157(2):439-47. PMC: 1163871. DOI: 10.1042/bj1570439. View

4.
Walker G, Mortenson L . Effect of magnesium adenosine 5'-triphosphate on the accessibility of the iron of clostridial azoferredoxin, a component of nitrogenase. Biochemistry. 1974; 13(11):2382-8. DOI: 10.1021/bi00708a023. View

5.
Thorneley R . Nitrogenase of Klebsiella pneumoniae. A stopped-flow study of magnesium-adenosine triphosphate-induce electron transfer between the compeonent proteins. Biochem J. 1975; 145(2):391-6. PMC: 1165229. DOI: 10.1042/bj1450391. View