Zonal rotor analysis of the subcellular localization of alpha-glycerphosphate dehydrogenase, alpha-naphthyl palmitate and beta-naphthyl laurate hydrolases in the mucosa of the guinea-pig small intestine.

Whole homogenate of guinea-pig small intestine mucosa was analysed by centrifugation in a zonal rotor. The results indicate that FAD-linked alpha-glycerophosphate dehydrogenase is localized in the mitochondria and that NAD-linked alpha-glycerophosphate dehydrogeanse is a soluble phase enzyme. An enzyme hydrolysing alpha-naphthyl palmitate at an acid pH was localized in the lysosomes and was activated by 0.1% Triton X-100 and by freezing and thawing. An alkaline hydrolase acting on beta-naphthyl laurate was localized in the 'microsomes'. The possibility of this enzyme being different from alpha-naphthyl acetate hydrolase is discussed.