Kinetic studies of liver alcohol dehydrogenase

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Abstract
Initial-rate data are reported for the liver-alcohol-dehydro-genase reaction with substrates ethanol and acetaldehyde at pH 6.0 and 7.1, and butanol and butyraldehyde at pH 7.1. The results for both pairs of substrates are consistent with the essential features of the mechanism proposed by Theorell and Chance (1951) whereby certain parameters of the initial-rate equation are identified with the specific rates of the reversible reaction of the enzyme and the coenzymes. Deviations from the strict requirements of a compulsory-order mechanism are observed, however, and several other simple mechanisms are inconsistent with the results, fa agreement with other workers, it is suggested that a more general mechanism involving alternative active pathways through binary coenzyme and substrate compounds of the enzyme will best account for the results. Conditions under which this mechanism approximates to the Theorell-Chance mechanism, and may also account for the discrepancies, are deduced.