Isoenzyme Profiles of a-Mannosidase and /3-Galactosidase in Leukemic Cells*)

The isoenzyme profiles of a-mannosidase and ,8-galactosidase in leukemic cells were examined with DEAE-Sephadex chromatography. A clear difference of these constituent isoenzymes was found between normal lymphocytes and granulocytes. In leukemic cells, the components of a-mannosidase eluting early (fraction I to III) from the chromatography were specific for myelogenous leukemia. No case of acute non-T/ non-B lymphocytic leukemia (ALL) or T-cell leukemia demonstrated these components. Leukemic cells except for T-cell leukemia also demonstrated significant increase of an a-mannosidase component which eluted with 0. 2 M of KCl (fraction VI). There was no type specific alteration of ,8-galactosidase isoenzymes among examined leukemias. ALL and T-cell leukemia had isoenzymes of ,8-galactosidase similar to those of normal lymphocytes. However, an increase of an ,8-galactosidase component eluted with 0. 3M of KCl (fraction VII) was found in acute myelocytic leukemia and chronic myelo (mono) cytic leukemia. These enzyme analysis may be useful for investigating intrinsic abnormalities in leukemic cells. acute myelocytic leukemia (AML)16>. 207