Rate constants for a mechanism including intermediates in the interconversion of ternary complexes by horse liver alcohol dehydrogenase

Biochemistry ◽  
1990 ◽  
Vol 29 (18) ◽  
pp. 4289-4295 ◽  
Author(s):  
V. Chandra Sekhar ◽  
Bryce V. Plapp
Keyword(s):  
Alcohol Dehydrogenase ◽  
Rate Constants ◽  
Ternary Complexes ◽  
Horse Liver Alcohol Dehydrogenase ◽  
Liver Alcohol Dehydrogenase ◽  
Horse Liver

Kinetic Mechanism for the Major Isoenzyme of Horse Liver Alcohol Dehydrogenase

1972 ◽  
Vol 50 (12) ◽  
pp. 1385-1413 ◽  
Author(s):  
Charles S. Hanes ◽  
Patricia M. Bronskill ◽  
Patricia A. Gurr ◽  
J. Tze-Fei Wong
Keyword(s):  
Sensitivity Analysis ◽  
Reaction Mechanism ◽  
Alcohol Dehydrogenase ◽  
Rate Constants ◽  
Kinetic Mechanism ◽  
Ternary Complexes ◽  
Binary Complex ◽  
Liver Alcohol Dehydrogenase ◽  
Horse Liver ◽  
High Concentrations

The reaction mechanism for the major isoenzyme C1 of the alcohol dehydrogenase (EC 1.1.1.1) of horse liver has been established through kinetic analysis utilizing direct correlations between rate and mechanistic features. The mechanism consists of random sequences of reaction of the enzyme with ethanol and NAD, and an obligatory sequence of reaction with NADH and acetaldehyde. At high concentrations of ethanol or NADH, excess-ethanol and excess-NADH pathways become evident involving the formation of an enzyme/NADH/ethanol complex. Even after dissociation of NADH from this complex the enzyme/ethanol complex remains imprinted with an altered conformation and differs from the regular binary complex formed under conditions of low ethanol concentrations. A range of elementary rate constants pertaining to the binding and dissociation of reactants from binary as well as ternary complexes of the mechanism has been estimated by means of a combination of algebraic analysis, curve simulation, and sensitivity analysis.

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