... biological activity has yet been described:YTTGKLPYGYGPGG (residues 221-234, released byMMP-7, MMP-9, and MMP-12), YGARPGVGVG-GIP (residues 383–395, released by MMP-12), andTable 4. (continued)Fig. ... less accessible to large polar or aromaticresidues such as Ser, Lys, Arg, Phe, and Tyr, whereasit easily accommodates medium-sized hydrophobic res-idues, including Leu and the even bulkier Ile[5,44,45,76,77], ... revealed further differences inthe MMP binding cleft. The polar residue Thr214 ofMMP-12 is mutated to an aliphatic residue in MMP-9(Val398) and MMP-7 (Ala215), and Glu219 of MMP-7and MMP-12...