Anti-Human MMP-14 (MT1-MMP)

Matrix metalloproteinases (MMPs) are a family of enzymes that are responsible for the degradation of extracellular matrix components.

Of the eleven proteins reported to date, ten are normally found as soluble molecules.

The eleventh, and newest of these proteins, has been named MT-MMP for membrane bound MMP.

MT-MMP contains a C-terminal transmembrane domain which allows it to localize to the cell surface.

It is also unique from the other members of the MMP family in that it contains an 8 amino acid insert in the catalytic domain.

The protein is encoded by a 4.5 kb mRNA species giving rise to a protein with a molecular weight of 60-66 kDa by SDS-PAGE.

MT-MMP is responsible for cleaving gelatinase A (MMP-2, 72 kDa Type IV collagenase) to the active form.

Evidence exists to suggest that MT-MMP itself requires an activation step which is most likely the result of activity of the membrane plasmin cascade.

MT-MMP functions by binding TIMP-2 and then the COOH terminal end of MMP-2 resulting in a 105 kDa trimer which effects the cleavage of pro-MMP-2 to the biologically active form.

The order of the binding of pro-MMP-2 and TIMP-2 to MT-MMP is critical as TIMP-2 will also inhibit the activity of MMP-2 when present in a soluble form.

Since its discovery, a second form of MT-MMP has been identified resulting in a change in the name of the original protein to MT1-MMP.