101. Characterization of Hex S, the major residual beta hexosaminidase activity in type O Gm2 gangliosidosis (Sandhoff-Jatzkewitz disease)
- Author
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Ikonne, J U, Rattazzi, M C, and Desnick, R J
- Subjects
Brain Chemistry ,Electrophoresis ,integumentary system ,Myocardium ,Syndrome ,Hydrogen-Ion Concentration ,Chromatography, Ion Exchange ,Kidney ,carbohydrates (lipids) ,Molecular Weight ,Hexosaminidases ,Liver ,embryonic structures ,Humans ,Enzyme Inhibitors ,Gangliosidoses ,Lung ,Spleen ,Research Article - Abstract
Hex S, the major residual beta hexosaminidase activity present in tissues, fluids, and cultured skin fibroblasts of patients with type 0 GM2 gangliosidosis, was isolated and characterized biochemically and immunologically. when appropriate tissue homogenates were tested by electrophoresis on cellulose acetate gels, hex S as well as hex C, the corresponding minor beta hexosaminidase component found in normal visceral tissues, migrated with greater anodic mobilities than hex A. However, a small but reproducible electrophoretic difference was observed between partially purified hex S and hex C components. Hex S and hex C had slightly higher apparent molecular weights than those of hex A or hex G; no major differences were found between hex S and hex A in thermostability, pH optimum, or kinetic properties. Hex S, like hex C from placenta, reacted with an antiserum directed towards the unique antigenic determinants alpha of hex A, indicating that hex S, hex C, and hex A share a common antigenic determinant. No reactivity of hex S was detected with an antiserum directed toward the common antigenic determinant beta of hex A and hex B. These results suggest that further biochemical and immunologic characterization of hex S and elucidation of its relationships with hex A, hex B, and hex C may significantly contribute to the understanding of the molecular defects in the GM2 gangliosidoses.
- Published
- 1975