Matrix metalloproteinase 2 from human rheumatoid synovial fibroblasts. Purification and activation of the precursor and enzymic properties

Eur J Biochem. 1990 Dec 27;194(3):721-30. doi: 10.1111/j.1432-1033.1990.tb19462.x.


Human rheumatoid synovial cells in culture secrete at least three related metalloproteinases that digest extracellular matrix macromolecules. One of them, termed matrix metalloproteinase 2 (MMP-2), has been purified as an inactive zymogen (proMMP-2). The final product is homogeneous on SDS/PAGE with Mr = 72,000 under reducing conditions. The NH2-terminal sequence of proMMP-2 is Ala-Pro-Ser-Pro-Ile-Ile-Lys-Phe-Pro-Gly-Asp-Val-Ala-Pro-Lys-Thr, which is identical to that of the so-called '72-kDa type IV collagenase/gelatinase'. The zymogen can be rapidly activated by 4-aminophenylmercuric acetate to an active form of MMP-2 with Mr = 67,000, and the new NH2-terminal generated is Tyr-Asn-Phe-Phe-Pro-Arg-Lys-Pro-Lys-Trp-Asp-Lys-Asn-Gln-Ile. However, following 4-aminophenylmercuric acetate activation, MMP-2 is gradually inactivated by autolysis. Nine endopeptidases (trypsin, chymotrypsin, plasmin, plasma kallikrein, thrombin, neutrophil elastase, cathepsin G, matrix metalloproteinase 3, and thermolysin) were tested for their abilities to activate proMMP-2, but none had this ability. This contrasts with the proteolytic activation of proMMP-1 (procollagenase) and proMMP-3 (prostromelysin). The optimal activity of MMP-2 against azocoll is around pH 8.5, but about 50% of activity is retained at pH 6.5. Enzymic activity is inhibited by EDTA, 1,10-phenanthroline or tissue inhibitor of metalloproteinases, but not by inhibitors of serine, cysteine or aspartic proteinases. MMP-2 digests gelatin, fibronectin, laminin, and collagen type V, and to a lesser extent type IV collagen, cartilage proteoglycan and elastin. Comparative studies on digestion of collagen types IV and V by MMP-2 and MMP-3 (stromelysin) indicate that MMP-3 degrades type IV collagen more readily than MMP-2, while MMP-2 digests type V collagen effectively. Biosynthetic studies of MMPs using cultured human rheumatoid synovial fibroblasts indicated that the production of both proMMP-1 and proMMP-3 is negligible but it is greatly enhanced by the treatment with rabbit-macrophage-conditioned medium, whereas the synthesis of proMMP-2 is constitutively expressed by these cells and is not significantly affected by the treatment. This suggests that the physiological and/or pathological role of MMP-2 and its site of action may be different from those of MMP-1 and MMP-3.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Arthritis, Rheumatoid / enzymology*
  • Blotting, Western
  • Cells, Cultured
  • Collagen / metabolism
  • Electrophoresis, Polyacrylamide Gel
  • Endopeptidases / metabolism
  • Enzyme Activation
  • Extracellular Matrix Proteins / isolation & purification*
  • Extracellular Matrix Proteins / metabolism
  • Fibroblasts / enzymology
  • Fibronectins / metabolism
  • Humans
  • Hydrogen-Ion Concentration
  • Laminin / metabolism
  • Metalloendopeptidases / antagonists & inhibitors
  • Metalloendopeptidases / isolation & purification*
  • Metalloendopeptidases / metabolism
  • Molecular Sequence Data
  • Substrate Specificity
  • Synovial Membrane / enzymology*


  • Extracellular Matrix Proteins
  • Fibronectins
  • Laminin
  • Collagen
  • Endopeptidases
  • Metalloendopeptidases