Changes in proteolytic activities of human leukemic promyelocytes (HL-60 cells) during maturation.
Proteolytic activity was measured in human leukemic promyelocytic cell line (HL-60) grown in culture, before and after the addition of agents which promote differentiation. The 36000 X g soluble fraction of the cells degraded [14C]globin with maximal activity at pH 3.6, while the insoluble fraction had a pH optimum at 8.0. This pattern did not change upon differentiation. The acid protease activity of the soluble fraction increased following differentiation. After 4 days in the presence of dimethyl sulfoxide, the differentiated cells exhibited 4-fold higher specific activity as compared with 4 day-old control cells. In contrast, the alkaline activity of the insoluble fraction of the differentiated cells was 4-fold lower than that of the undifferentiated cells. It is suggested that the changes in enzyme activities may serve the new functions acquired by the mature granulocytes.
D016282:Aspartic Acid Endopeptidases; D002460:Cell Line; D010450:Endopeptidases / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D015470:Leukemia, Myeloid, Acute / Q000201:enzymology*; D008247:Lysosomes / Q000201:enzymology; D010447:Peptide Hydrolases / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology
D011480:Protease Inhibitors; D006026:Glycoside Hydrolases; D010450:Endopeptidases; D010447:Peptide Hydrolases; D016282:Aspartic Acid Endopeptidases