Inhibits thermolysin, bacillolysin and pseudolysin, B.polymyxa metalloprotease and human MMP1 and MMP3. No activity on trypsin or cysteine protease papain. Expressed in fat body of last instar larvae. During humoral immune response (PubMed:9738891). By lipopolysaccharide (LPS) (PubMed:15115439). Induced by A.niger alpha-1,3-glucan (PubMed:34443685). Cleaved. Five disulfide bonds are present. When artificially cleaved by thermolysin between Asn-56 and Ile-57, the two obtained chains (called heavy and light chains) remain linked. The N-terminus is blocked.