Tissue fractionation studies. 15. Intracellular distribution and properties of β-N-acetylglucos-aminidase and β-galactosidase in rat liver

Abstract

The intracellular distribution of [beta]-N-acetylglucosaminidase and of [beta]-galactosidase has been investigated in rat liver according to a fractionation scheme in which the mitochondrial fraction is divided into two subtractions. It was found to differ distinctly from those of the mitochondria! cytochrome oxidase and of the microsomal glucose 6-phosphatase and to parallel closely that of the lysosomal acid phosphatase. Like acid phosphatase, both enzymes occurred largely in latent form in fresh particulate preparations. Treatments which caused a release of acid phosphatase liberated the [beta]-glycosidases in approximately the same proportion. In both types of experiments, small but significant differences were observed in the behavior of the three hydrolases. It is concluded from these results that the two [beta]-glycosidases are associated with the lysosomes and the differences observed are attributed to the heterogeneity of this class of particles, already revealed by previous investigations.