Aminopeptidases in human leukemia cells

: Aminopeptidase activity in lymphoid cells of patients with various lymphoproliferative diseases was studied. The enzyme activity was detected in lysates of all leukemic B- and T-cells. The lymphoid cells contained aminopeptidases of at least two classes: metallo- and SH-dependent enzymes. The SH-dependent aminopeptidase with pH optimum 8.5-9.0 was revealed in lymphoid cells for the first time, and it seems to belong to a poorly studied aminopeptidase family.