Cleaves host elastase, collagen, IgI and several complement components as well as endogenous pro-aminopeptidase, pro-chitin-binding protein (cbpD). Cleaves its own pro-peptide. Involved in the pathogenesis of P.aeruginosa infections. Hydrolysis of proteins including elastin, collagen types III and IV, fibronectin and immunoglobulin A, generally with bulky hydrophobic group at P1'. Insulin B chain cleavage pattern identical to that of thermolysin, but specificity differs in other respects. Binds 1 Ca(2+) ion per subunit. Binds 1 Zn(2+) ion per subunit. Made as a pre-pro-protein which is exported to the periplasm. Probably autocatalyzes cleavage of its pro-peptide. The pro-peptide can be secreted with mature elastase. Belongs to the peptidase M4 family.