Component forms of Acid Hydrolases in Subcellular Granules from Human Leucocytes

Abstract

During the last decade, the basic enzyme defects of many lysosomal storage disorders have been elucidated and this has led to the development of relatively simple laboratory tests for their precise diagnosis. The routine application of such tests has revealed that variant forms of these disorders usually exist and that these variants are often characterised by relative deficiencies of the component activities of a multi-component enzyme. A fuller understanding of the clinical, genetic, and biochemical differences between such variants will require detailed investigations into the physicochemical and biological characteristics of the component forms of the enzymes associated with each disorder. For many types of cell there is considerable evidence of heterogeneity of hydrolase-containing particles, and it is possible that this reflects some differentiation of their digestive functions. In the case of a multi-component hydrolase, this differentiation might be manifested further in the variable distribution of these components in the different particles. Knowledge of such variable distribution might then help to explain the biological functions of the enzyme components, This report is concerned with the resolution and subcellular localisation of the component forms of N-acetyl-β-D-glucosaminidase, the lysosomal hydrolase associated with Tay-Sachs disease and its variants.