A leucine-specific metalloprotease that plays a role in controlling the amount of leupeptin during colony development. Degrades leupeptin into three components, acetyl-leucine, leucine and argininal. Has a strict preference for leucine at the P1 site. Binds 2 Zn(2+) ions per subunit. Activity is inhibited by metalloprotease inhibitors and activated by Mg(2+) and Ca(2+). Optimum pH is 9.0. Optimum temperature is 40 degrees Celsius. Monomer. Belongs to the peptidase M28 family. M28A subfamily.