Processing Enzymes Acting on Carbohydrate Moiety of Lysosomal Hydrolases in Leukemic Cells: Elevated Activity of N Acetylglucosamine-

We previously demonstrated that an acidic variant form of lysosomal arylsulfatase B accumulated in chronic myelogenous leukemia (CML) cells was highly phosphorylated at its carbohydrate moiety (Uehara Y. et al. Cancer Res 435618. 1983). Since lysosomal hydrolases including the sulfatase underwent the posttranslational phosphorylation processing at the carbohydrate moiety, we investigated two enzymes acting on the processing in peripheral leukocytes from leukemia patients. The activity level of the first enzyme in the processing, an N-acetylglucosamine1 -phosphotransferase to form phosphodiester at the carbohydrates. was significantly higher in CML cells than in normal control. The transferase level in CML cells was also