Has an integral role during the infection of macrophages in the mammalian host. Preference for hydrophobic residues at P1 and P1' and basic residues at P2' and P3'. A model nonapeptide is cleaved at -Ala-Tyr-|-Leu-Lys-Lys-. Binds 1 zinc ion per subunit. The phosphatidylinositol moiety of the GPI-anchor contains a fully saturated, unbranched 1-O-alkyl chain (mainly C24:0) and a mixture of fully saturated unbranched 2-O-acyl chains (C12:0, C14:0, C16:0, and C18:0). Belongs to the peptidase M8 family.