Organ Distribution of Aldehyde Dehydrogenase Activity in the Newt

Abstract

Aldehyde dehydrogenases are NAD-dependent enzymes that catalyze the oxidation of aldehydes to carboxylic acids. Three major classes of mammalian aldehyde dehydrogenase (ALDH) are recognized (Lindahl, 1992). Class 1 is cytosolic and NAD-specific. Class 2 is mitochondrial, also uses NAD, and preferentially functions at micromolar concentrations of small aliphatic aldehydes. Class 1 and 2 are tetramers of identical subunits. The monomers have a molecular weight of 55 kD. Class 3 ALDH preferentially uses NAD, but can use NADP. Class 3 oxidizes aromatic aldehydes such as benzaldehyde. The enzyme is a dimer of identical monomers with molecular weights of 50kD.