Matrix metalloproteinases (MMPs) are a group of 16 enzymes that are capable of degrading extracellular matrix components. Their catalytic function is dependent on a zinc ion in the active center. MMPs are separated in three groups: gelatinases (type IV-collagenases), stromelysins, and interstitial collagenases. Their physiological and pathological significance is to modulate the extracellular matrix—e. g., in embryogenesis, in the ovarian cycles, or in inflammatory diseases such as rheumatoid arthritis or fibrosis of the liver or kidney (1 ,2 ).
