THE N‐ACETYL‐β‐d‐HEXOSAMINIDASES OF CALF AND HUMAN BRAIN

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Abstract
Abstract— Multiple forms of calf brain N‐acetyl‐β‐hexosaminidases (β‐2‐acetamido‐2‐ deoxy‐d‐glucoside acetamidodeoxyglucohydrolase EC 3.2.1.30) were separated on starch gel electrophoresis at pH 5.8. The organ specific electrophoretic patterns did not depend on the cell fraction studied. Much of the activity is only separated with difficulty from particulate matter. Two major and one minor component were separated on DEAE‐cellulose chromatography at pH 5.8. Each component had both N‐acetyl‐β‐galactosaminidase and N‐acetyl‐β‐glucosaminidase activity. The ratio of these two activities was unaffected by the presence of N‐ethylmaleimide or dithiothreitol. The forms were also examined by isoelectric focusing when at least four components were recognized: isoelectric at 4.9, 6.0, 6.3 and 6.8. Interconversion of the 4.9 form to that isoelectric at pH 6.0 was noted during vacuum dialysis. Samples from normal human brain and from cases of Tay‐Sachs disease were also examined and the results compared.