European Journal of Biochemistry · 1985 · 16 citations · 14 references
Natural SciencesBiochemistryChemistryChemical KineticsEnzyme MechanismEnzymologyBinding KineticsCatalytic MechanismsEnzyme KineticsLigand Binding KineticsMichaelis-menten KineticsStructural EnzymologyAssociation ConstantsAssociation Rate ConstantsDehydrogenase ComplexesDissociation Rate ConstantsEnzyme Kinetic AnalysisKinetic MeasurementKinetics Of Complex DissociationRate Constants
One molecule of the enzymatic intermediate histidinal is firmly bound per subunit of histidinol dehydrogenase (EC 1.1.1.23) and protected against decomposition. The dissociation rate constant of the histidinal--histidinol dehydrogenase complex is estimated as 2.5 X 10(-5) S-1. Steady-state kinetic measurements studying the oxidation of histidinal to histidine and the reduction of histidinal to histidinol allow to calculate the association rate constants for histidinal. For both reactions the association rate constant is found as 1.9 X 10(6) M-1 S-1. Thus the dissociation constant of the histidinal--histidinol dehydrogenase complex is estimated to be of the order of 1.4 X 10(-11) M.
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