The mechanism of Klebsiella pneumoniae nitrogenase action. Pre-steady-state kinetics of H2 formation
- 15 December 1984
- journal article
- research article
- Published by Portland Press Ltd. in Biochemical Journal
- Vol. 224 (3) , 877-886
- https://doi.org/10.1042/bj2240877
Abstract
A comprehensive model for the mechanism of nitrogenase action is used to simulate pre-steady-state kinetic data for H2 evolution in the presence and in the absence of N2, obtained by using a rapid-quench technique with nitrogenase from K. pneumoniae. These stimulations use independently determined rate constants that define the model in terms of the following partial reactions: component protein association and dissociation, electron transfer from Fe protein to MoFe protein coupled to the hydrolysis of MgATP, reduction of oxidized Fe protein by NA2S2O4, reversible N2 binding by H2 displacement and H2 evolution. Two rate-limiting dissociations of oxidized Fe protein from reduced MoFe protein precede H2 evolution, which occurs from the free MoFe protein. Fe protein suppresses H2 evolution by binding to the MoFe protein. This is a necessary condition for efficient N2 binding to reduced MoFe protein.This publication has 18 references indexed in Scilit:
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