The normal physiological role of BLM hydrolase is unknown, but it catalyzes the inactivation of the antitumor drug BLM (a glycopeptide) by hydrolyzing the carboxamide bond of its B-aminoalaninamide moiety thus protecting normal and malignant cells from BLM toxicity. Inactivates bleomycin B2 (a cytotoxic glycometallopeptide) by hydrolysis of a carboxyamide bond of beta-aminoalanine, but also shows general aminopeptidase activity. The specificity varies somewhat with source, but amino acid arylamides of Met, Leu and Ala are preferred. Strongly inhibited by leupeptin, puromycin, NEM, and divalent cations. Homohexamer (By similarity). Interacts with NUDT12 (via ANK repeats) (By similarity). Co-localizes with NUDT12 in the cytoplasmic granules. Belongs to the peptidase C1 family.