– May be involved in tissue injury and remodeling. Has significant elastolytic activity. Can accept large and small amino acids at the P1′ site, but has a preference for leucine. Aromatic or hydrophobic residues are preferred at the P1 site, with small hydrophobic residues (preferably alanine) occupying P3. MMP-12 Protein, Human, Recombinant (His) is expressed in E. coli expression system with N-6xHis tag. The predicted molecular weight is 46.1 kDa and the accession number is P39900.