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A trypsin sensitive stromelysin isolated from rheumatoid synovial fluid is an activator for matrix metalloproteinases
H Kolkenbrock1, A Hecker-Kia, D Orgel
1Deutsches Rheuma-Forschungszentrum Berlin, AG Biochemie, Germany.
Abstract:
The processing of synovial fluids of patients suffering from rheumatoid arthritis led to the characterization of a neutral metalloproteinase with polymorphonuclear leukocyte progelatinase and polymorphonuclear leukocyte procollagenase activating properties. The activator exhibits a relative molecular mass of M(r) 27,000 and is an active form of stromelysin. Thus, it reacts specifically with antibodies raised against human stromelysin, splits polymorphonuclear leukocyte progelatinase in a manner characteristic of stromelysin, and is inhibited by EDTA as well as by a tissue inhibitor of metalloproteinases (TIMP-2). The activator shows a high specificity for the matrix metalloproteinases, polymorphonuclear leukocyte progelatinase and polymorphonuclear leukocyte procollagenase. It shows only weak hydrolysis of casein and gelatin, and it does not activate fibroblast M(r) 72,000 progelatinase. Brief treatment with trypsin does not lead to a significant change in the activator's relative molecular mass, but induces a rapid loss of its activating activity for polymorphonuclear leukocyte progelatinase, while its proteolytic activity against the synthetic substrate, N-(2,4)-dinitrophenyl-Pro-Gln-Gly-Ile-Ala-Gly-Gln-D-Arg, is increased about 3-fold. The same tryptic treatment does not affect the activator's proteolytic activity towards casein and gelatin.
Insights
Researchers identified a neutral metalloproteinase in rheumatoid arthritis patients
Area of Science:
- Biochemistry
- Rheumatology
- Enzymology
Background:
- Rheumatoid arthritis (RA) involves complex inflammatory processes.
- Synovial fluid in RA patients contains various enzymes, including metalloproteinases.
- Understanding these enzymes is crucial for RA pathogenesis and treatment.
Purpose of the Study:
- To characterize a novel neutral metalloproteinase from rheumatoid arthritis synovial fluid.
- To investigate its specific enzymatic activities and properties.
Main Methods:
- Synovial fluid processing from rheumatoid arthritis patients.
- Protein characterization using molecular mass determination and antibody specificity tests.
- Enzyme activity assays for progelatinase and procollagenase activation.
- Inhibition studies with EDTA and tissue inhibitor of metalloproteinases-2 (TIMP-2).
Main Results:
- A neutral metalloproteinase (M(r) 27,000) was isolated and identified as an active form of stromelysin.
- The enzyme specifically activates polymorphonuclear leukocyte (PMN) progelatinase and PMN procollagenase.
- It shows high specificity for matrix metalloproteinases and is inhibited by EDTA and TIMP-2.
- Trypsin treatment reduced PMN progelatinase activation but increased synthetic substrate hydrolysis.
Conclusions:
- The characterized enzyme is a potent activator of PMN progelatinase and procollagenase, likely contributing to matrix degradation in rheumatoid arthritis.
- Its properties align with active stromelysin, highlighting its role in rheumatoid arthritis pathogenesis.
- Further research into this stromelysin form could offer therapeutic targets for rheumatoid arthritis.