Matrix Metalloproteinases

Matrix metalloproteinases (MMPs), also known as matrix metallopeptidases or matrixins, are a family of zinc-dependent proteolytic enzymes that degrade various proteins in the extracellular matrix (ECM). MMPs belong to the large metzincin superfamily of metalloproteases, like the astacins, serralysins, reprolysins, and adamalysins or disintegrin metalloproteinases (ADAMs). MMPs are encoded by 24 human (including a duplicated MMP-23 gene) and 23 mouse genes. The MMP family can be divided into at least six subfamilies: (1) collagenases; (2) gelatinases, (3) stromelysins, (4) matrilysins, (5) MMP membrane-type (MT)-MMPs, and (6) other MMPs. A typical MMPs consists of an N-terminal zymogenic propeptide domain (~80 amino acids), a metal-dependent catalytic domain (~170 amino acids), a linker region (~15-65 amino acids), and a C-terminal hemopexin-like domain (~200 amino acids). All MMPs are synthesized as proenzymes and require a proteolytic cleavage under physiological conditions to promote the release of the propeptide domain (zymogen activation) and generate mature MMPs. MMPs play a central role in many biological processes, such as embryogenesis, normal tissue remodeling, wound healing, and angiogenesis, and in diseases such as atheroma, arthritis, cancer, and tissue ulceration.