Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.23 (MMP)
 4,246 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The uterus of the rat contains a small metalloproteinase that digests Azocoll and proteoglycan. The activity of this enzyme is elevated in the postpartum uterus and parallels the rate of breakdown of matrix proteoglycan (Sellers, A. and Woessner, J.F., Jr., Biochem. J. 189: 521, 1980). The enzyme has been purified to homogeneity. Its molecular weight is 28,000 for the latent form of the enzyme and 19,000 for the active form, as determined by SDS/PAGE. The enzyme has no action on collagens of type I, III, IV or V, but it does digest gelatins of these 4 types. Digestion of type I gelatin is most pronounced for the alpha-2 chain, which is cleaved to two major bands. The B chain of insulin is cleaved at Ala14-Leu15 and Tyr16-Leu17. Proteoglycan is degraded, but no action can be detected against elastin. Both zinc and calcium ions are required for activity. Low levels of phosphoramidon or Zincov are not inhibitory. Detailed comparisons with human gelatinase (matrix metalloproteinase 2) and stromelysin (matrix metalloproteinase 3) show that the uterine proteinase has a distinctive pattern of specificity. The properties match those of human Pump-1 as reported by Quantin et al., Biochemistry 28: 5327, 1989. It is proposed to designate this proteinase as matrix metalloproteinase 7.
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PMID:The small matrix metalloproteinase of the rat uterus. 148 88

A metalloproteinase with Mr 29,000 was purified to homogeneity as a latent proenzyme from the conditioned medium of a human rectal carcinoma cell line CaR-1. This enzyme hydrolyzed casein more potently than gelatin embedded in polyacrylamide gels in zymography assay. Calcium ion was essential for the activity. It exerted the maximum activity at pH 7-9. Its activity was stimulated by organomercurials, such as p-amino-phenyl mercuric acetate and p-chloromercuric benzoic acid, and was inhibited by 1,10-phenanthroline but was hardly affected by diisopropyl fluorophosphate and pepstatin. When the purified proenzyme was activated by the organomercurials, it effectively hydrolyzed fibronectin, laminin, type IV basement membrane collagen, and several types of gelatins but not interstitial type I and III collagens. The treatment of the purified proenzyme with p-aminophenyl mercuric acetate or trypsin formed an active peptide with Mr 20,000. The structural analysis indicated that it was most likely identical to putative metalloproteinase-1, the complementary DNA of which had been cloned from human tumor mRNAs capable of hybridizing to a rat transin complementary DNA. Based on the fact that this enzyme is secreted extracellularly and degrades the matrix proteins, we propose the name "matrin" for this newly identified enzyme.
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PMID:Purification and characterization of extracellular matrix-degrading metalloproteinase, matrin (pump-1), secreted from human rectal carcinoma cell line. 225 19

A small metalloproteinase that digests Azocoll was found in the uterus of the rat. Its activity increased to high levels during the postpartum period in parallel with the breakdown of the extracellular matrix exclusive of collagen (Sellers, A., and Woessner, J.F., Jr. (1980) Biochem. J. 189, 521-531). This enzyme has now been purified almost 7,000-fold to homogeneity from 12 g of tissue using molecular sieve chromatography, blue sepharose chromatography, and zinc-chelate chromatography. Gel electrophoresis with sodium dodecyl sulfate and dithiothreitol gives Mr = 28,000 for the latent form of the enzyme and Mr = 19,000 for the active form that arises spontaneously or by treatment with aminophenylmercuric acetate. The enzyme digests components of the extracellular matrix including gelatins of types I, III, IV, and V, fibronectin, and proteoglycan. It digests the alpha 2(I) chain of gelatin in preference to the alpha 1(I) chain and cleaves dinitrophenyl-Pro-Leu-Gly-Ile-Ala-Gly-Pro-D-Arg. It cleaves the B chain of insulin at two points: Ala14-Leu15 and Tyr16-Leu17. It has no action on collagens of types I, III, IV, or V at 26 degrees C and no action on elastin or phenylazo-Pro-Leu-Gly-Pro-D-Arg. The pH optimum is at pH 7 and the pI at 5.9. The enzyme requires zinc and calcium ions for activity; cobalt and strontium can partially replace these metal ions. The enzyme is not inhibited by low levels of phosphoramidon or Zincov. Its properties clearly distinguish it from collagenase, gelatinase (matrix metalloproteinase 2), and stromelysin (matrix metalloproteinase 3); it therefore constitutes a further member of the family of extracellular matrix metalloendopeptidases. The name matrix metalloproteinase 7 is proposed.
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PMID:Purification and properties of a small latent matrix metalloproteinase of the rat uterus. 318 22

Analysis of bovine interphotoreceptor matrix and conditioned medium from human Y-79 retinoblastoma cells by gelatin SDS-PAGE zymography reveals abundant activity of a 72-kDa M(r) gelatinase. The 72-kDa gelatinase from either source is inhibited by EDTA but not aprotinin or NEM, indicating that it is a metalloproteinase (MMP). The 72-kDa MMP is converted to a 62-kDa species with APMA treatment after gelatin sepharose affinity purification, typical of previously described gelatinase MMP-2. The latent 72-kDa gelatinase from either bovine IPM or Y-79 media autoactivates without APMA in the presence of calcium and zinc after 72 hr at 37 degrees C, producing a fully active mixture of proteinase species, 50 (48 in Y-79 medium), 38 and 35 kDa in size. The presence of inhibitory activity was examined in both whole bovine IPM and IPM fractions separated by SDS-PAGE. Whole IPM inhibited gelatinolytic activity of autoactivated Y-79-derived MMP in a dose-dependent manner. Inhibitory activities are observed in two protein fractions of 27-42 and 20-25 kDa. Western blots using antibodies to human tissue inhibitor of metalloproteinase 1 and 2 (TIMP-1 and -2) reveal the presence of two TIMP-1-like proteins at 21 and 29 kDa in inhibitory fractions of the bovine IPM. TIMP-2 was not detected in the inhibitory IPM fractions, consistent with the observed autoactivation of bovine IPM 72-kDa gelatinase. Potential roles for this IPM MMP-TIMP system include physiologic remodelling of the neural retina-RPE cell interface and digestion of shed rod outer segment as well as pathological processes such as retinal detachment, PE cell migration, neovascularization and tumor progression. Cultured Y-79 cells appear to be a good model for studying the production and regulation of this proteinase system.
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PMID:Characterization and novel activation of 72-kDa metalloproteinase in retinal interphotoreceptor matrix and Y-79 cell culture medium. 782 70

Structural luteolysis was found decades ago to be induced by PRL in the hypophysectomized rat, but the mechanisms of this process are unknown. To gain information on mechanisms of luteal involution, we developed an animal model that circumvented complex surgery and provided ample tissue for analyses. Gonadotropin-synchronized ovulation and luteinization were induced in immature rats, followed by treatment with ergot alkaloid and PRL. PRL-induced structural luteolysis, as shown by loss of luteal weight, protein, and DNA after pretreatment with ergot alkaloid, was evident after 36 h. Ascorbic acid depletion was rapid, severe, and lasting in luteal tissue during structural luteolysis, but lipid peroxidation or depletion of vitamin E was not evident. PRL treatment of animals with functional corpora lutea did not induce luteal involution. Significantly, after natural functional luteolysis occurred, PRL was highly effective in inducing structural luteolysis. Thus, either natural or ergot-induced functional luteolysis permitted the luteolytic expression of PRL. A greater depletion of protein than DNA was seen during PRL-induced structural luteolysis and was associated with a significant increase in neutral caseinase activity in luteal extracts. Caseinase activity was markedly reduced by calcium chelators and profoundly inhibited by the chelator orthophenanthroline; only slightly reduced activity was seen with serine, aspartate, or cysteine proteinase inhibitors. These findings implicate metalloproteinase (MMP) as the relevant caseinase that was increased during structural luteolysis. The major proteinase identified by zymography had apparent sizes of 72 and 66 kilodaltons (kDa), and slight but detectable activity was also seen at 92 and 84 kDa. Organomercurial treatment caused a major shift of the 72-kDa band to 66 kDa and the 92-kDa band to 84 kDa, confirming MMP-2 and MMP-9 by activation of latent activity of each MMP, respectively. Structural luteolysis caused a significant increase in the activated 66-kDa form and the latent 72-kDa form of MMP-2, which occurred before a loss of luteal weight or protein. As MMP-2 degrades collagen (type IV) in basement membranes, we conclude that an early event in PRL-induced structural luteolysis is the degradation of extracellular matrix. This conclusion is further emphasized by the marked and lasting depletion of ascorbic acid, a vitamin long known to serve an essential role in collagen synthesis.
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PMID:Coordinate induction and activation of metalloproteinase and ascorbate depletion in structural luteolysis. 834 7

Human pro-MMP-3 (pro-matrix metalloproteinase-3) was purified from three sources: articular cartilage and conditioned media from synovial fibroblasts and Chinese hamster ovary cells expressing recombinant pro-MMP-3. All three preparations reacted with two monoclonal antibodies specific for human fibroblast pro-MMP-3. Each preparation of active MMP-3 possessed properties identical to those previously reported for the cartilage acid metalloproteinase (MMP-6; Azzo and Woessner, J. F., Jr. (1986) J. Biol. Chem. 261, 5434-5441): an acid pH optimum of 5.3-5.5 for digestion of cartilage aggrecan; digestion of oxidized insulin B-chain at Ala14-Leu15 and Tyr16-Leu17 in a ratio of 3:1; and heat stability at neutral pH. Further characterization of MMP-3 establishes that the acid pH optimum for cartilage aggrecan is not due to substrate denaturation since the same optimum is found by viscosity assay, by SDS-polyacrylamide gel electrophoresis assay of G1 domain, and by digestion of aggrecan in fresh cartilage fragments in vitro. Fibronectin was also digested optimally at pH 5.5 and NH2-terminal sequence analysis revealed no pH change in a major proteolytic site of cleavage at the Pro689-Leu690 bond. The specificity constant kcat/Km is maximal at pH 5.5 as determined in a quenched fluorescence peptide assay. This is due to an increase in kcat at pH 5.5 without any substantial effect on Km. The affinity of MMP-3 for calcium is decreased about 10-fold at pH 5.3 compared to neutral pH. Finally, the neutral cartilage metalloproteinase is identified as 72-kDa pro-MMP-2 based on M(r), specificity of insulin B-chain cleavage, and reactivity with a specific polyclonal antibody to human MMP-2.
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PMID:Matrix metalloproteinase-3 (stromelysin-1). Identification as the cartilage acid metalloprotease and effect of pH on catalytic properties and calcium affinity. 840 46

Recombinant human fibroblast pro-MMP-3 (prostromelysin-1) expressed in Chinese hamster ovary cells and the zymogen from cultured human dermal fibroblasts have been purified by monoclonal antibody immunoaffinity chromatography, and the role of Ca2+ in proenzyme activation and thermostability of the low mass catalytic domain of MMP-3 has been investigated. In the presence of high Ca2+ (5.0 mM), the organomercurial aminophenylmercuric acetate (APMA) initiated the stepwise removal of both NH2- and COOH-terminal domains from both recombinant and dermal fibroblast proenzymes, resulting in the generation of a heterogeneous family of nonglycosylated low mass truncated active enzyme species beginning at Phe83. However, in the presence of low Ca2+ (0.1 mM), incubation of recombinant pro-MMP-3 with or without APMA did not result in formation of either the high or low mass forms of active MMP-3 but resulted in complete autolysis of both enzyme species. The concentration of Ca2+ required for optimal pro-MMP-3 activation and stability of the low mass catalytic domain was 2.0 mM. The low mass truncated enzyme species containing the catalytic domain were remarkably heat-stable (90 min at 60 degrees C) in high Ca2+ (5.0 mM) but rapidly autolyzed when heated at 60 degrees C in low Ca2+ (0.1 mM). The thermostability properties of MMP-3 appeared to be specific for Ca2+, since no other divalent metal ions tested were able to confer thermostability to the low mass catalytic domain of MMP-3. From homology to the thermostable bacterial metalloprotease, thermolysin, two putative Ca2+ binding sites were found in the catalytic domain of MMP-3 and several other members of the MMP gene family. These putative Ca2+ binding sites are postulated to play an important role in stabilizing active MMP-3 and other members of the matrix metalloprotease gene family by protecting them against autolysis.
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PMID:Recombinant Chinese hamster ovary cell matrix metalloprotease-3 (MMP-3, stromelysin-1). Role of calcium in promatrix metalloprotease-3 (pro-MMP-3, prostromelysin-1) activation and thermostability of the low mass catalytic domain of MMP-3. 844 Jul 30

Gelatinase B (MMP-9), a member of the matrix metalloproteinase family, is a zinc- and calcium-dependent endopeptidase that is known to play a role in tumor cell invasion and in destruction of cartilage in arthritis. It contains a conserved sequence. 400His-(X)3-His-(X)28-Asp-Asp-(X)2-436Gly, the function of which is under investigation. The conserved Asp-432 and Asp-433 residues were individually replaced with Gly; these substitutions reduced the gelatinolytic activity of the enzyme to 23% and 0%, respectively. Replacing Asp-433 with Glu, however, decreased the gelatinolytic activity of the enzyme by 93% and proteolytic activity of the enzyme for the Mca-Pro-Leu-Gly-Leu-Dpa-Ala-Arg-NH2 substrate by 79%. The wild-type and D432G and D433E, mutant enzymes had similar Km values for the synthetic substrate and similar Ki values for the competitive inhibitor, GM6001. The kcat/Km values for D432G and D433E mutant enzymes, however, were reduced by a factor of approximately 4 and their KaCa values were increased by four- and sixfold, respectively. The significance of His-400 in the activity of the enzyme was assessed by replacing this residue with Ala and Phe. Both H400A and H400F mutants were inactive toward gelatin substrate. These data demonstrate that Asp-432, Asp-433, and His-400 residues are important for the activity of gelatinase B. His-400 may act as a zinc-binding ligand similar to the His-197 in interstitial collagenase (MMP-7) and Asp-432 and Asp-433 residues are probably involved in stabilization of the active site of the enzyme. The His-400 and Asp-433 residues are conserved in all members of the MMP family. Therefore, our results are relevant to this group as a whole.
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PMID:Role of the conserved histidine and aspartic acid residues in activity and stabilization of human gelatinase B: an example of matrix metalloproteinases. 856 49

Human matrix metalloproteinase-7 (MMP-7 = matrilysin) was overproduced in Escherichia coli as a recombinant zymogen (31 kDa), the C-terminus of which bears artificial hexa-histidines. Most of the enzyme was isolated from the insoluble fraction of the cell lysate and purified by a single step using Ni-NTA resin after solubilization of the precipitates with 8 M urea solution. The resin-bound recombinant protein was refolded into a form that is activatable by p-amino-phenylmercuric acetate in an autocatalytic manner. The activated enzyme cleaved a synthetic peptide substrate at the reported site for MMP-7. Digestion of carboxymethylated transferrin (a natural substrate of MMP-7) by the recombinant proteinase generated fragments with the same peptide map as in the case of native purified MMP-7. The autocatalytic activation and enzyme reaction were entirely dependent on the presence of calcium and zinc ions. The enzyme activity to cleave carboxymethylated transferrin was inhibited by tissue inhibitors of metalloproteinases-1 and -2, MMP-specific inhibitors. The activity of the recombinant MMP-7 was also inhibited by a synthetic peptide derived from a part of the cysteine switch that maintains the zymogen in an inactive state. Thus, we report here a simple means of preparing a large quantity of recombinant proMMP-7 that can be used to study the activation mechanism and to screen synthetic inhibitors.
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PMID:Purification and refolding of recombinant human proMMP-7 (pro-matrilysin) expressed in Escherichia coli and its characterization. 874 67

Fibulin-1 and fibulin-2 are two novel rod-like proteins which occur either in basement membranes or in interstitial fibrils in close association with fibronectin. They were examined for their sensitivity to proteolysis by matrix metalloproteinases (stromelysin, matrilysin), circulating proteases (thrombin, plasmin, kallikrein), leucocyte elastase and mast cell chymase. Fibulin-1 (95 kDa) was readily cleaved by leucocyte elastase, weakly by matrilysin and not by the other proteases. Cleavage occurred in a domain-connecting link region close to the N-terminus, giving rise to fragments of 70 kDa and 26 kDa. A much more extensive cleavage by all seven proteases was observed for fibulin-2 (195 kDa), giving rise to many fragments in the range 15-150 kDa. Vulnerable sites included two central link regions, the cysteine-free part of the large N-terminal globular domain but also several regions of epidermal-growth-factor(EGF)-like repeats which are a major part of the rod-like domain. The latter domain became much more sensitive to proteolysis in the presence of EDTA, demonstrating that calcium is required for stabilization. Edman degradation demonstrated cleavage of peptide bonds corresponding to the known specificities of these proteases. A similar proteolysis was also observed for fibulin-2 deposited by cultured fibroblasts into a dense fibrillar network. Since fibulin-2 is an abundant component of small and large blood vessels it could be a major target for proteolysis during vascular injuries.
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PMID:Different susceptibilities of fibulin-1 and fibulin-2 to cleavage by matrix metalloproteinases and other tissue proteases. 884 8


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