The Kinetics of Pig Brain Aldehyde Dehydrogenase

Abstract

1 The enzyme kinetics of semi-purified pig brain aldehyde dehydrogenase have been investigated. 2 The form of the basic double reciprocal plots and plots in the presence of known concentrations of NADH are consistent with a compulsory order reaction pathway in which NAD+ is bound first, followed by the aldehyde. The products are released in a fixed order, acid first then NADH. 3 The overall reaction is irreversible, and proceeds to completion. Acid products are not inhibitory. This is consistent with the release of acid products being irreversible. 4 The form of inhibition by high aldehyde concentrations is consistent with the proposed reaction pathway. 5 Apparent substrate activation is observed with acetaldehyde and propionaldehyde.