Aldehyde dehydrogenases, aldehyde oxidase and xanthine oxidase from baboon tissues: phenotypic variability and subcellular distribution in liver and brain.

Isoelectric focusing (IEF) and cellulose acetate electrophoresis were used to examine the multiplicity and distribution of aldehyde dehydrogenases (ALDHs), aldehyde oxidase (AOX) and xanthine oxidase (XOX) from tissues of olive and yellow baboons. Five ALDHs were resolved and distinguished on the basis of their differential tissue and subcellular distribution or substrate specificity. Some ALDHs exhibited multiple activity zones. Baboon liver ALDHs were differentially distributed in cytosol (ALDHs II, III and V) and large granular (mitochondrial) fractions (ALDHs I and IV). The major liver ALDHs (I and II) were also broadly distributed in other tissues, as was the major stomach enzyme (ALDH-III). Three brain ALDHs were resolved, which were also differentially distributed between large granular (mitochondrial) (ALDHs I and IV) and cytosolic (ALDH-III) fractions. Electrophoretic variability between individuals was observed for the major liver mitochondrial isozyme (ALDH-I), the major stomach isozyme (ALDH-III) and the minor liver isozymes (ALDHs IV and V). Single forms of AOX and XOX were found in baboon tissue extracts, with the highest activities in liver (AOX) and intestine extracts (XOX). Both oxidases were predominantly localized in the liver soluble fraction.