Steps involved in activation of the pro-matrix metalloproteinase 9 (progelatinase B)-tissue inhibitor of metalloproteinases-1 complex by 4-aminophenylmercuric acetate and proteinases.

Abstract

The precursor of matrix metalloproteinase 9 (pro-MMP-9, progelatinase B) noncovalently binds to tissue inhibitor of metalloproteinases (TIMP)-1 through the C-terminal domain of each molecule. We have isolated the proMMP-9.TIMP-1 complex from the medium of human fibrosarcoma HT-1080 cells and investigated the activation processes of the complex by 4-aminophenylmercuric acetate, trypsin, and matrix metalloproteinase 3 (MMP-3, stromelysin 1). The treatment of the proMMP-9.TIMP-1 complex with 4-aminophenylmercuric acetate or trypsin converts proMMP-9 to lower molecular weight species corresponding to active forms, but no gelatinolytic activity is detected. The lack of enzymic activity results from binding of TIMP-1 to the activated MMP-9. The treatment of the proMMP-9.TIMP-1 complex with a possible physiological proMMP-9 activator, MMP-3, does not reveal any gelatinolytic activity unless the molar ratio of MMP-3 to the complex exceeds 1. This is due to the inhibition of MMP-3 by TIMP-1 forming a ternary proMMP-9.TIMP-1.MMP-3 complex. The formation of the ternary complex weakens the interaction between proMMP-9 and TIMP-1, resulting in partial dissociation of the complex into proMMP-9 and the TIMP-1.MMP-3 complex. When MMP-3 is in excess, the propeptide is completely processed, and the full activity of MMP-9 is detected. Similarly, the proMMP-9.TIMP-1 complex inhibits MMP-1 (interstitial collagenase) and in turn renders the proMMP-9 activable by a catalytic amount of MMP-3. These results suggest that formation of the proMMP-9.TIMP-1 complex regulates extracellular matrix breakdown in tissue by switching the predominant MMP activity from one type to another.

• Authors: Y Ogata, Y Itoh, H Nagase
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 270 Issue 31 Pg. 18506-11 (Aug 04 1995) ISSN: 0021-9258 [Print] United States
• PMID: 7629179 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Enzyme Precursors
• Glycoproteins
• Macromolecular Substances
• Tissue Inhibitor of Metalloproteinases
• 4-aminophenylmercuriacetate
• Trypsin
• Collagenases
• Metalloendopeptidases
• Matrix Metalloproteinase 3
• Matrix Metalloproteinase 9
• Phenylmercuric Acetate

Topics

• Collagenases (metabolism)
• Enzyme Activation (drug effects)
• Enzyme Precursors (metabolism)
• Extracellular Matrix (metabolism)
• Glycoproteins (metabolism)
• Humans
• Macromolecular Substances
• Matrix Metalloproteinase 3
• Matrix Metalloproteinase 9
• Metalloendopeptidases (metabolism)
• Phenylmercuric Acetate (analogs & derivatives, pharmacology)
• Protein Binding
• Tissue Inhibitor of Metalloproteinases
• Trypsin (pharmacology)
• Tumor Cells, Cultured