Isoenzyme studies in human leukemia -- III. beta-Hexosaminidase (E.C. 3.2.1.30).

Enzymologic profiles of beta-hexosaminidase (N-acetyl-beta-D-glucosaminidase, E.C.3.2.1.30) were studied in cells from childhood acute leukemias and lymphomas. By analytical isoelectric focusing or disc electrophoresis the beta-hexosaminidase activity was separated into its components A, B, I and C. The isoenzyme patterns were correlated with immunologic cell surface marker characteristics found on the investigated leukemic cells. In all cases of T-ALL the beta-hexosaminidase forms A and B were observed, an enzyme pattern similar to that found in normal lymphocytes. Seven out of 11 cases with cALL, three of six cases with AML and one case of AUL displayed the intermediate component (Hex I). Marked heterogeneity within the immunologically classified subgroup cALL was reflected in different enzyme patterns of the cALL samples. These biochemical phenotypes may indicate the different maturation and differentiation status of cells expressing the same immunologic surface markers.