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

Extracellular matrix metalloproteases are synthesized as proenzymes and are activated by certain physiological agents after secretion into the extracellular space. The identity of these agents and the stimulus that elicits their response in vivo is only recently becoming clear, but a variety of agents or stimuli are capable of activating these metalloproteases in vitro also. Of these, the most well studied and characterized are trypsin, plasmin and the organomercurials. These agents appear to have in common an ability to disrupt the structure of the stable latent enzyme in such a way as to allow the generation of a proteolytic active site. In the case of organomercurial activation, intramolecular proteolytic cleavage of the amino-terminus of the enzyme occurs subsequent to generation of activity. A similar intramolecular process is seen with trypsin and plasmin activation except that it is initiated by a single trypsin or plasmin catalyzed cleavage in the amino-terminus prior to the autocatalytic cleavages. A possible explanation for organomercurial activation is that the mercurial disrupts a cysteinyl residue coordination bond with the active site zinc that prevents interaction with substrate. Disruption of this complex would allow productive enzyme-substrate interaction via the newly available coordination site. In addition, activated stromelysin is capable of increasing the specific activity of active interstitial collagenase by approximately ten-fold through what appears to be proteolytic removal of a small peptide.
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PMID:Activation of extracellular matrix metalloproteases by proteases and organomercurials. 148 30

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.
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PMID:Primary structure and function of stromelysin/transin in cartilage matrix turnover. 148 63

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 determination of the zinc stoichiometry of the catalytic domain of the human matrix metalloproteinase stromelysin-1 has been carried out using enzyme purified from recombinant Escherichia coli that express C-terminally truncated protein. Atomic absorption spectrometry revealed that both the proenzyme (prostrom255) and the mature active form (strom255) contained nearly 2 mol of Zn/mol of protein. Full-length prostromelysin purified from a mammalian cell culture line also contained zinc in excess of 1 equiv. While zinc in prostrom255 could not be removed by dialysis against o-phenanthroline, similar treatment of mature strom255 resulted in the loss of one-half of the original zinc content. The peptidase activity of the zinc-depleted protein was reduced by greater than 85% but could be restored upon addition of Zn2+ or Co2+. Addition of a thiol-containing inhibitor to a CoZn hybrid enzyme resulted in marked spectral changes in both the visible and ultraviolet regions characteristic of sulfur ligation to Co2+. This direct evidence for an integral role in catalysis and inhibitor binding confirms the location of the exchangeable metal at the active site. To examine the environment of zinc in the proenzyme, a fully cobalt-substituted proenzyme was prepared by in vivo metal replacement. The absorbance features of dicobalt prostrom255 were consistent with metal coordination by the single cysteine present in the propeptide, although the data do not allow assignment to a particular zinc site.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Characterization of zinc-binding sites in human stromelysin-1: stoichiometry of the catalytic domain and identification of a cysteine ligand in the proenzyme. 158 8

L-696,474, an inhibitor of the HIV-1 protease, was discovered in extracts of the fungal culture Hypoxylon fragiforme (MF5511; ATCC 20995). L-696,474 is a novel cytochalasin with a molecular weight of 477 and an empirical formula of C30H39NO4. L-696,474 inhibited HIV-1 protease activity with an IC50 of 3 microM and the mode of inhibition was competitive with respect to substrate (apparent Ki = 1 microM). Furthermore, L-696,474 was not a slow-binding inhibitor. The inhibition due to L-696,474 was also independent of the HIV-1 protease concentration. L-696,474 was inactive against pepsin, another aspartyl protease; stromelysin, a zinc-metalloproteinase; papain, a cysteine-specific protease or human leucocyte elastase, a serine-specific protease. Two other novel cytochalasins (L-697,318 and L-696,475) isolated from the same culture were inactive against the HIV-1 protease. Commercially available cytochalasins B, C, D, E, F, H and J were inactive while cytochalasin A was as active as L-696,474 against the HIV-1 protease.
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PMID:L-696,474, a novel cytochalasin as an inhibitor of HIV-1 protease. III. Biological activity. 162 71

Activation of procollagenase constitutes a crucial event in collagenolytic activity regulation. In this study we have purified by DEAE-cellulose, Ultrogel AcA-44, and zinc chelate sepharose chromatographies, a procollagenase-activator from the culture medium of the guinea pig carrageenin granuloma model. On SDS-PAGE, the activator migrates as a principal band of Mr approximately 44,000. The molecule activates procollagenase from human lung fibroblasts in a concentration dependent manner and an enhancement of collagenase activity of trypsin-treated crude culture medium was observed. A loss of about 50% of its activity occurs after heating. In addition, this activator degrades gelatin and casein. All these data suggest that this procollagenase-activator might be stromelysin. The activator was found in both phases of the granuloma, at 7 days when collagen is actively deposited and an important proportion of the collagenolytic activity remains in latent form; and at 14 days, when this enzymatic activity is fully expressed.
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PMID:Purification of a procollagenase-activator present in medium of cultured guinea pig carrageenin granuloma. 166 Aug 1

The 72- and 92-kDa type IV collagenases are members of a group of secreted zinc metalloproteases. Two members of this family, collagenase and stromelysin, have previously been localized to the long arm of chromosome 11. Here we assign both of the two type IV collagenase genes to human chromosome 16. By sequencing, the 72-kDa gene is shown to consist of 13 exons, 3 more than have been reported for the other members of this gene family. The extra exons encode the amino acids of the fibronectin-like domain which has so far been found in only the 72- and 92-kDa type IV collagenase. The evolutionary relationship among the members of this gene family is discussed.
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PMID:On the structure and chromosome location of the 72- and 92-kDa human type IV collagenase genes. 185 24

Rous sarcoma virus-transformed rat liver cell line RSV-BRL secreted a neutral proteinase in a latent precursor form with a molecular weight (Mr) of 57,000 (57k) as a major secreted protein. This enzyme was a calcium-dependent metallo-proteinase. The proenzyme was purified from the serum-free conditioned medium of the transformed cells by affinity chromatographies on a zinc chelate Sepharose column and a reactive red agarose column. When activated by treatment with trypsin or p-aminophenylmercuric acetate (APMA) in the presence of Ca2+, the purified enzyme effectively hydrolyzed casein, fibronectin, and laminin. Type IV collagen was hydrolyzed at 37 degrees C but not at 30 degrees C by the enzyme, whereas type I and type III collagens were hardly hydrolyzed even at 37 degrees C. The treatment with trypsin or AMPA in the presence of Ca2+ converted this 57k proenzyme to an active and stable enzyme with Mr 42k. In the absence of Ca2+, however, APMA converted the proenzyme to an intermediate form with Mr 45k, while trypsin digested it to an inactive peptide with Mr 30k. These results demonstrate that calcium ion is essential for the activation, activity expression, and stabilization of this metallo-proteinase. Analysis of its partial amino acid sequence and amino acid composition showed that the 57k proenzyme was identical or closely related to the putative protein transin, a rat homologue of stromelysin.
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PMID:Purification and properties of extracellular matrix-degrading metallo-proteinase overproduced by Rous sarcoma virus-transformed rat liver cell line, and its identification as transin. 196 30

The family of mammalian extracellular matrix metalloproteases (MMPs) are secreted by cells in an inactive (latent) proenzyme form. A highly conserved amino acid sequence, PRCGVPDV, is found near the COOH-terminal end of the pro-domain of these MMPs and believed to act as an "autoinhibitor." Recent studies (Springman, E. B., Angleton, E. L., Birkedal-Hansen, H., and Wart, H. E. V. (1990) Proc. Natl. Acad. Sci. U. S. A. 87, 364-368) indicate the Cys of this sequence ligands to the active-site zinc keeping the proenzyme in an inactive state, and mutational analysis (Sanchez-Lopez, R., Nicholson, R., Gesnel, M. C., Matrisian, L. M., and Breathnach, R. (1988) J. Biol. Chem. 263, 11892-11899) suggests that the conserved residues surrounding this Cys are required for latency. We have constructed 16 new site-directed mutations of the PRCGVPDV autoinhibitor region of the MMP transin (rat stromelysin) and tested whether these mutant enzymes are produced in a latent or activated form. We find that the conserved Arg as well as the Cys are essential for maintaining latency. The Cys cannot be replaced by other zinc-liganding amino acids, and the Arg cannot be replaced by Lys. Residues immediately surrounding the Cys are sensitive to even conservative amino acid substitutions. We show that a synthetic peptide PRCGVPDV is capable of acting as a weak inhibitor of transin and that replacement of the Cys with a Ser abolishes inhibition by the peptide. A review of the current knowledge of MMP substrate specificity in combination with these new results suggests that the PRCGVPDV sequence does not inhibit activity by mimicking the known substrates of the protease.
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PMID:Mutational analysis of the transin (rat stromelysin) autoinhibitor region demonstrates a role for residues surrounding the "cysteine switch". 198 38

Extracellular matrix turnover is initiated, at least in part, by the regulated secretion of members of a family of matrix metalloproteinases. The authors show that interstitial collagenase, stromelysin, two gelatinases (the 72-kD and 92-kD type IV collagenases), and the tissue inhibitor of metalloproteinases (TIMP) are secreted into the culture medium of human retinal pigment epithelium (RPE). These enzymes and their inhibitor were identified by probing immunoblots of western transfers with specific polyclonal antibodies that were made against these proteins or against peptides containing unique sequences from these proteins. Stromelysin and the gelatinases are also active against substrates that are polymerized into polyacrylamide gel before electrophoresis and require metal ions (probably zinc and/or calcium) for activity. The phorbol mitogen, 12-tetradecanoylphorbol-13-acetate, differentially increases the levels of these metalloproteinases and TIMP found in retinal pigment epithelium culture medium with stromelysin and the 92-kD type IV collagenase responding most strongly and TIMP actually decreasing in certain cases. Additional changes in metalloproteinase profiles are observed after approximately 20 passage of several RPE lines in culture. Modulation of extracellular matrix turnover by changing RPE secretion of these matrix metalloproteinases and their TIMP, may play a central role in the normal function and in the pathology of the retina.
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PMID:Expression of matrix metalloproteinases and inhibitor by human retinal pigment epithelium. 217 83


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