Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.17 (MMP-3)
 3,419 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Collagenase production by rodent osteoblasts in response to calciotropic hormones has led to the hypothesis that bone cells play a major role in bone resorption by degrading the surface osteoid layer, thereby exposing the underlying mineralized matrix to osteoclastic action. Many studies suggest, however, that this model might not apply to bone resorption in the human. Human osteoblasts have been shown to produce gelatinase-A (72 kDa) and TIMP-1 (tissue inhibitor of metalloproteinases), but previous investigators have been unable to demonstrate the synthesis of collagenase by human osteoblasts either constitutively or in response to bone resorptive agents. In the present study the ability of human osteoblasts to produce the matrix metalloproteinases (MMPs) collagenase, gelatinase and stromelysin, and their specific inhibitors TIMPs-1 and 2, was examined using highly sensitive and specific antisera and by zymography. Semi-quantitative histomorphometric data showed that cells cultured on either glass or a type I collagen substratum constitutively synthesized gelatinase-A and TIMP-1. On type I collagen, however, a small proportion of unstimulated cells produce both collagenase (7%) and gelatinase-B (95 kDa; 3%). Treatment of cells with either parathyroid hormone (PTH), 1,25-dihydroxy-vitamin D3 (1,25(OH)2D3), or partially purified mononuclear cell conditioned medium (MCM), stimulated the synthesis of collagenase, gelatinase-B and stromelysin; MCM was 2- to 3-fold more potent than either PTH or 1,25(OH)2D3. Zymography using SDS/PAGE on conditioned media from cells cultured on type I collagen films revealed the presence of active gelatinase-A and that MCM stimulated progelatinase-B synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Human osteoblasts in culture synthesize collagenase and other matrix metalloproteinases in response to osteotropic hormones and cytokines. 133 77

The effects of the chondroprotective drugs, sodium pentosan polysulphate (SP54) and Arteparon (glycosaminoglycan polysulphate), on the in vitro activities of the purified matrix metalloproteinases interstitial collagenase (matrix metalloproteinase 1, MMP1) and stromelysin (MMP3) were examined. Both drugs produced concentration-dependent enhancement of the degradation of type I collagen fibrils by purified human fibroblast collagenase and rat tumour collagenase. Rat collagenase activity was increased by drug concentrations above 0.5 microgram/mL, whereas human collagenase activity was only increased by higher drug concentrations, above 5 micrograms/mL. The concentration dependence of the increase in rat collagenase activity was similar for both drugs, with a maximal 3-fold increase at 50 micrograms/mL. In contrast, human collagenase activity was increased to a greater extent by SP 54 compared to Arteparon, with maximal increases at 5000 micrograms/mL of 6-fold and 2-4-fold, respectively. Both drugs produced concentration-dependent inhibition of the proteoglycan-degrading activity of both human fibroblast stromelysin and rat tumour stromelysin. Rat and human stromelysin activities were inhibited at drug concentrations above 0.005 microgram/mL, with a similar concentration dependence for both drugs. Fifty percent inhibition of rat stromelysin was produced by concentrations of each drug in the 0.5-5 microgram/mL range. The pattern of inhibition of human stromelysin was similar, except that drug concentrations in the 500-5000 micrograms/mL range produced 50% inhibition. The possible modes of action for these drug effects and their possible pharmacological significance are discussed.
 ...
PMID:The chondroprotective drugs, Arteparon and sodium pentosan polysulphate, increase collagenase activity and inhibit stromelysin activity in vitro. 138 3

Matrix metalloproteinase 9 (MMP-9) has been purified as an inactive zymogen of M(r) 92,000 (proMMP-9) from the culture medium of HT 1080 human fibrosarcoma cells. The NH2-terminal sequence of proMMP-9 is Ala-Pro-Arg-Gln-Arg-Gln-Ser-Thr-Leu-Val-Leu-Phe-Pro, which is identical to that of the 92-kDa type IV collagenase/gelatinase. The zymogen can be activated by 4-aminophenylmercuric acetate, yielding an intermediate form of M(r) 83,000 and an active species of M(r) 67,000, the second of which has a new NH2 terminus of Met-Arg-Thr-Pro-Arg-(Cys)-Gly-Val-Pro-Asp-Leu-Gly-Arg-Phe-Gln-Thr- Phe-Glu. Immunoblot analyses demonstrate that this activation process is achieved by sequential processing of both NH2- and COOH-terminal peptides. TIMP-1 complexed with proMMP-9 inhibits the conversion of the intermediate form to the active species of M(r) 67,000. The proenzyme is fully activated by cathepsin G, trypsin, alpha-chymotrypsin, and MMP-3 (stromelysin 1) but not by plasmin, leukocyte elastase, plasma kallikrein, thrombin, or MMP-1 (tissue collagenase). During the activation by MMP-3, proMMP-9 is converted to an active species of M(r) 64,000 that lacks both NH2- and COOH-terminal peptides. In addition, HOCl partially activates the zymogen by reacting with an intermediate species of M(r) 83,000. The enzyme degrades type I gelatin rapidly and also cleaves native collagens including alpha 2 chain of type I collagen, collagen types III, IV, and V at undenaturing temperatures. These results indicate that MMP-9 has different activation mechanisms and substrate specificity from those of MMP-2 (72-kDa gelatinase/type IV collagenase).
 ...
PMID:Matrix metalloproteinase 9 (92-kDa gelatinase/type IV collagenase) from HT 1080 human fibrosarcoma cells. Purification and activation of the precursor and enzymic properties. 140 Apr 81

Stromelysin/Transin is a member of the matrix metalloprotease gene family. This metalloprotease is synthesized as a preproenzyme with a predicted size of 53,977 Da including a 17 amino acid signal peptide. Prostromelysin is secreted from normal and transformed cells in two forms with apparent molecular masses on NaDodSO4 gels of 60 and 58-kDa. The minor 60-kDa species contains N-linked oligosaccharide(s). Stromelysin consists of three domains the amino terminal propeptide(s) domain contains the tribasic amino acid sequence RRK which is important in the proteolytic activation of this zymogen by trypsin-like serine proteases. The second domain consists of the catalytic domain which contains the zinc binding site. The carboxyl-terminal hemopexin domain has no known function and can be removed without a loss of enzymatic activity. Stromelysin has a broad range of substrate specificity including proteoglycans, casein, fibronectin, laminin, native type IV and IX collagen and gelatin but not type I collagen. In the presence of trypsin or plasmin, catalytic amounts of this enzyme can also fully activate interstitial fibroblast collagenase. We have developed a panel of monoclonal antibodies against stromelysin which will be useful for the tissue localization of the various species of this enzyme in tissues. In addition, we have demonstrated that either human rIL-1 (alpha) or rTNF (alpha) can stimulate the expression of this enzyme in cultured bovine articular cartilage at least 10-fold. Based on western blot analysis, the zymogen form of the enzyme was the major enzyme species detected in either the media or cartilage matrix compartments of cytokine treated cultures.
 ...
PMID:Primary structure and function of stromelysin/transin in cartilage matrix turnover. 148 63

The serine proteinase acrosin plays an important role in sperm penetration of the zona pellucida. In the present study we investigated the effect of the enzyme on various matrix proteins. Acrosin degraded proteolytically fibronectin, type IV collagen and heat denatured type I collagen, whereas neither native type I collagen nor laminin were cleaved by the enzyme. The specific activity of acrosin with type IV collagen as substrate (66.6 g/h/g) was 125-fold higher than that of known type IV collagenase or stromelysin. These results suggest that acrosin may act as a matrix-degrading proteinase.
 ...
PMID:Matrix degrading properties of sperm serine proteinase, acrosin. 166 89

We have studied the degradation of type X collagen by human skin fibroblast and rat uterus interstitial collagenases and human 72-kDa type IV collagenase. The interstitial collagenases attacked the native type X helix at two loci, cleaving residues Gly92-Leu93 and Gly420-Ile421, both scissions involving Gly-X bonds of Gly-X-Y-Z-A sequences. However, the human and rat interstitial enzymes displayed an opposite and substantial selectivity for each of these potential sites, with the uterine enzyme catalyzing the Gly420-Ile421 cleavage almost 20-fold faster than the Gly92-Leu93 locus. Values for enzyme-substrate affinity were approximately 1 microM indistinguishable from the corresponding Km values against type I collagen. Interestingly, in attacking type X collagen, both enzymes manifested kinetic properties intermediate between those characterizing the degradation of native and denatured collagen substrates. Thus, energy dependence of reaction velocity revealed a value of EA of 45 kcal, typical of native interstitial collagen substrates. However, the substitution of D2O for H2O in solvent buffer failed to slow type X collagenolysis significantly (kH/kD = 1.1), in contrast to the 50-70% slowing (kH/kD = 2-3) observed with native interstitial collagens. Since this lack of deuterium isotope effect is characteristic of interstitial collagenase cleavage of denatured collagens, we investigated the capacity of another metalloproteinase with substantial gelatinolytic activity, 72-kDa type IV collagenase, to degrade type X collagen. The 72-kDa type IV collagenase cleaved type X collagen at both 25 and 37 degrees C, and at loci in close proximity to those attacked by the interstitial enzymes. No further cleavages were observed at either temperature with type IV collagenase, and although values for kcat were not determined (due to associated tissue inhibitor of metalloproteinases-2), catalytic rates appeared to be substantial in comparison to the interstitial enzymes. In contrast, type X collagen was completely resistant to proteolysis by stromelysin. Type X collagen thus appears to be highly unusual in its susceptibility to degradation by both interstitial collagenase and another member of the metalloproteinase gene family.
 ...
PMID:Differential susceptibility of type X collagen to cleavage by two mammalian interstitial collagenases and 72-kDa type IV collagenase. 216 34

Inactivation of the plasma serine-proteinase inhibitor alpha 1-antitrypsin (alpha 1-AT) by neutrophil metalloproteinases has been reported [Vissers, George, Bathurst, Brennan & Winterbourn (1987) Fed. Proc. Fed. Am. Soc. Exp. Biol. 46, 1390a; (1988) J. Clin. Invest. 82, 706-711; Desrochers & Weiss (1988) J. Clin. Invest. 81, 1646-1650]. To identify the enzyme responsible, supernatant from neutrophils stimulated with phorbol 12-myristate 13-acetate was subjected to preparative SDS/PAGE, both with and without activation of latent metalloproteinases with HgCl2. The lanes were subsequently sliced into pieces, the slices incubated with equimolar amounts of type I collagen and alpha 1-AT in the presence of HgCl2, and the reaction products separated by SDS/PAGE. With the latent supernatant, the characteristic collagen-cleavage products and cleaved alpha 1-AT were present in the same slices, corresponding to an Mr of 80,000-85,000. On treatment with HgCl2 both degradative activities underwent the same molecular-mass shift to a position corresponding to Mr 60,000-65,000. Western blots of neutrophil supernatants, using a polyclonal antibody to purified collagenase, showed Mr values of 83,000 for the latent enzyme and 63,000 for the HgCl2-activated enzyme. Neutrophil collagenase was purified to homogeneity and shown also to exist in a second latent form with Mr 70,000. When activated to the Mr-63,000 form by HgCl2 and incubated with equimolar amounts of collagen and alpha 1-AT, collagenase cleaved alpha 1-AT at almost twice the rate at which collagen was cleaved. alpha 1-AT cleavage was inhibited by 1,10-phenanthroline and by high concentrations of collagen. That the purified collagenase did not contain a contaminant proteinase such as stromelysin was indicated by inability of the preparation to cleave casein. Taken together these results lead us to conclude that neutrophil collagenase is capable of degrading alpha 1-AT. Neutrophil gelatinase also cleaved alpha 1-AT, but cleavage was slow when compared with its activity against gelatin.
 ...
PMID:Human neutrophil collagenase cleaves alpha 1-antitrypsin. 217 52

Conditions were established to stimulate human gingival fibroblast explant cultures to synthesize milligram quantities of the metalloproteinase proenzymes, prostromelysin and procollagenase. To stimulate enzyme production, cells were treated with 1 nM recombinant human IL-1 beta for approximately 7 days under serum free conditions. Using a combination of rapid column chromatography steps, approximately 10 milligrams of prostromelysin and 5 milligrams of procollagenase were purified from 1 liter of conditioned media. Prostromelysin electrophoresed as a doublet with molecular weights of 55,57 kD, whereas, procollagenase migrated with slightly lower molecular weights of 52, 54 kD. Both proenzymes were treated with trypsin or aminophenylmercuric acetate to generate active species. The molecular weights of the active enzymes were approximately 10 kD smaller than the proenzymes. Active enzymes were inhibited by metal chelators and the natural metalloproteinase inhibitor, tissue inhibitor of metalloproteinase (TIMP), but not by the serine protease inhibitor, phenylmethylsulfonyl fluoride (PMSF). Activated stromelysin degraded a number of substrates including transferrin, proteoglycan monomer, proteoglycan aggregated with hyaluronic acid, and substance P. By contrast, collagenase degraded interstitial type I collagen and the peptide thioester, Ac-Pro-Leu-Gly-SCH(iBu)Co-Leu-GlyOEt. Identity of both enzymes were confirmed by amino-terminal protein sequence analysis as well as by immunoblot analysis using monoclonal antibodies.
 ...
PMID:Production and purification of prostromelysin and procollagenase from IL-1 beta-stimulated human gingival fibroblasts. 217 90

The homologous proteinase inhibitors, human alpha 2-macroglobulin (alpha 2M) and chicken ovostatin, have been compared with respect to their "bait" region sequences and interactions with two human matrix metalloproteinases, collagenase and stromelysin. A stretch of 34 amino acid residues of the ovostatin bait region sequence was determined and the matrix metalloproteinase cleavage sites identified. Collagenase cleaved a X-Leu bond where X was unidentified, whereas the major cleavage site by stromelysin was at the Gly-Phe bond, 4 residues on the COOH-terminal side of the collagenase cleavage site. Collagenase cleaved the alpha 2M bait region at the Gly679-Leu680 bond, and stromelysin at Gly679-Leu680 and Phe684-Tyr685 bonds. Sequence similarity in the bait region of members of the alpha-macroglobulin family is strikingly low. The kinetic studies indicate that alpha 2M is a 150-fold better substrate for collagenase than type I collagen. Structural predictions based on the bait region sequences suggest that a collagen-like triple helical structure is not a prerequisite for the efficient binding of tissue collagenase to a substrate. The binding of stromelysin to alpha 2M is slower than that of collagenase. Stromelysin reacts with ovostatin even more slowly. Despite the preference of chicken ovostatin for metalloproteinases, human alpha 2M, a far less selective inhibitor, reacts more rapidly with collagenase and stromelysin. These results suggest that alpha 2M may play an important role in regulating the activities of matrix metalloproteinases in the extracellular space.
 ...
PMID:Interaction of human rheumatoid synovial collagenase (matrix metalloproteinase 1) and stromelysin (matrix metalloproteinase 3) with human alpha 2-macroglobulin and chicken ovostatin. Binding kinetics and identification of matrix metalloproteinase cleavage sites. 247 Jul 48

We previously suggested that periodontal pathogens might mediate connective tissue degradation in periodontal diseases through the ability of antigens from their cell walls to stimulate cytokine production by circulating mononuclear cells. Such cytokines would then induce metalloproteinase (MP) synthesis by resident gingival cells and thus initiate matrix degradation. In the present investigation human gingival fibroblasts (HGFs) were grown on [14C]-labelled type I collagen films and stimulated with either tumor necrosis factor (TNF) or interleukin-1 (IL-1) for 48 h. Collagenolysis occurred in a dose-dependent manner; the optimal dose for human rTNF alpha was 100 ng/ml and for rIL-1 alpha and rIL-1 beta, 1 ng/ml. Collagen degradation was accompanied by increased synthesis and release of the MPs collagenase, gelatinase and stromelysin, and there was a reduction in free TIMP (tissue inhibitor of metalloproteinases): collagenase and stromelysin were detected in both active and latent forms. Cytokine-stimulated collagenolysis was abolished by the addition of exogenous human rTIMP (5 units/ml). We also measured collagenase and TIMP by ELISAs which recognize all forms of collagenase (latent, active or complexed) and TIMP (free or complexed). These showed that while collagenase activity (0.6-1.2 microgram/ml) correlated with lysis, total TIMP levels remained unchanged at approximately 0.2 microgram/ml. These results demonstrate important roles for MPs and TIMP in regulating type I collagen degradation by HGFs, and support the hypothesis that connective tissue destruction during inflammatory diseases may be initiated, at least in part, by TNF and IL-1.
 ...
PMID:Gingival fibroblasts degrade type I collagen films when stimulated with tumor necrosis factor and interleukin 1: evidence that breakdown is mediated by metalloproteinases. 255 Jun 4


1 2 3 4 5 6 7 8 9 Next >>