Matrix Metalloproteinase (MMP)
A family of zinc-dependent enzymes that degrade extracellular matrix components. MMPs play essential roles in tissue remodelling during wound healing, embryonic development, and disease. Imbalanced MMP activity contributes to chronic wounds, arthritis, and tumour invasion.
Technical Context
MMPs are a family of 23+ zinc-dependent endopeptidases classified by substrate preference: collagenases (MMP-1, -8, -13 — cleave fibrillar collagens I/II/III at a specific Gly-Ile/Leu bond 3/4 from the N-terminus), gelatinases (MMP-2, -9 — degrade denatured collagen/gelatin, type IV collagen in basement membranes), stromelysins (MMP-3, -10, -11 — broad substrate range), matrilysins (MMP-7, -26 — small, no hemopexin domain), membrane-type MMPs (MMP-14/MT1-MMP — cell-surface anchored, activates MMP-2), and others. MMP activity is regulated at: transcription (induced by cytokines, growth factors, mechanical stress), activation (secreted as inactive zymogens, activated by proteolytic cleavage), and inhibition (by TIMPs). In wound healing, MMPs are essential for ECM remodelling and cell migration; in pathology, excessive MMP activity causes tissue destruction (chronic wounds, arthritis, tumour invasion). The MMP/TIMP balance is a key determinant of wound healing quality.