Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A model system consisting of highly purified lysyl oxidase and reconstituted lathyritic chick bone collagen fibrils was used to study the effect of collagen cross-linking on collagen degradation by mammalian collagenase. The results indicate that synthesis of approx. 0.1 Schiff-base cross-link per collagen molecule results in a 2--3-fold resistance to human synovial collagenase when compared with un-cross-linked controls or samples incubated in the presence of beta-aminopropionitrile to inhibit cross-linking. These results confirm previous studies utilizing artificially cross-linked collagens, or collagens isolated as insoluble material after cross-linking in vivo, and suggest that increased resistance to collagenase may be one of the earliest effects of cross-linking in vivo. The extent of intermolecular cross-linking among collagen fibrils may provide a mechanism for regulating the rate of collagen catabolism relative to synthesis in normal and pathological conditions.
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PMID:Native cross-links in collagen fibrils induce resistance to human synovial collagenase. 4 86

1. Hepatocytes were isolated by perfusion of the liver with collagenase/salt solutions and incubated in culture after attachment to plastic culture dishes for periods up to 48 h. 2. The cells, when incubated in serum-free culture medium in the presence of insulin, showed enhanced stearolyl-CoA desaturase activity which was not observed when 50 muM cycloheximide was included. When insulin was omitted from the medium, the cells lost 80% of their original desaturase activity. 3. Cells isolated from animals fed 20% (w/w) sucrose for two weeks prior to sacrifice, showed high levels of fatty acid synthesis, stearolyl-CoA desaturase activity and triacylglycerol synthesis when compared with cells isolated from animals fed a corn oil supplemental diet. 4. The observations are discussed in terms of the influence of stearoyl-CoA desaturase activity on hepatic lipogenesis.
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PMID:Stearolyl-CoA desaturase: a control enzyme in hepatic lipogenesis. 4 36

The ability of collagenase to disaggregate a solid metastasizing lymphosarcoma has been shown to considerably increase with reducing environmental pH. It is suggested that this effect may be operating in vivo to release cells from a primary tumour.
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PMID:Increased release of tumour cells by collagenase at acid pH: a possible mechanism for metastasis. 4 55

The Acinetobacter spec collagenase has been almost completely purified. This enzyme is a true collagenase the activity of which is high on collagen. The enzyme is active on insoluble collagen, gelatin and the synthetic Pz-peptide, but has no proteolytic activity on casein or bovine serum-albumin. The collagenase was obtained on a simple medium with gelatin and yeast extract. The enzyme was purified by (NH4)2SO4 precipitation. DEAE cellulose column chromatography, Sephadex G 200 gel-filtration. The molecular weight of the enzyme was found to be 102 000 daltons, and its isoelectric point was found to be 7,7 +/- 0,2. The optimum pH and temperature for insoluble collagen hydrolysis were 7.6 and 37 degrees C, respectively; so, this collagenase corresponds to true collagenase. Hydrolysis of Pz-peptide is activated by Ca2+ and inhibited by metal ions (Cu2+, Fe3+, Zn2+, Pb2+, Hg2+). EDTA and o-phenanthroline induced a very significant reduction in enzyme activity. Iodoacetate and p-CMB induced a slight reduction in enzyme activity only at high concentrations (10-2M). The collagenase is most stable for temperatures less than or equal to 50 degrees C.
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PMID:[Purification and physico-chemical properties of collagenase synthesized by a bacterium of the type Acinetobacter sp]. 4 44

Highly sensitive gelatin substrate films prepared according to a recent variant of the procedure are studied for their susceptibility to the action of various endopeptidases and exopeptidases. Trypsin, papain, elastase, and chymotrypsin are found to hydrolyze the gelatin films most easily, while higher enzyme concentrations are required in case of pepsin, plasmin and collagenase. The exopeptidases, i.e. leucine aminopeptidase, amino acid arylamidase and carboxypeptidases A and B do not cause lysis of gelatin substrate films. The example of a rabbit blastocyst protease involved in implantation is given to demonstrate the application of gelatin substrate film tests for studies of enzymes which have no or little activity against known synthetic substrates (like BANA or GPNA) but hydrolyze gelatin films. Studies of interactions of this blastocyst protease with various inhibitors of known specificity, however, show that the active center of this enzyme nevertheless has striking similarities to trypsin (and also to chymotrypsin). The enzyme is possibly related to elastase. It is emphasized that, besides this, there are a number of different protease type enzymes in rabbit blastocyst and uterine tissues, some of which can be demonstrated only with chromogenic substrates and some only by gelatin methods. Aspects of applicability of the two types of protease tests are briefly discussed.
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PMID:[The specificity and sensitivity of the gelatin base protease substrate film test ]. 4 23

Normal mouse spleen cells were fractionated in dishes coated with thin layers of DNP-gelatin or NIP-gelatin, which were insoluble at 4 degrees C. Highly viable cells were recovered from the dishes by melting the gel at 37 degrees C. NIP3- gelatin layers bound approximately 0.1% and DNP4-gelatin layers 0.5% of normal spleen cells. Increasing numbers of low affinity cells were bound with increasing DNP density of the adsorbent. The binding to insoluble DNP-gelatin was hapten-specific since it was inhibited by DNP-lysine, soluble DNP-gelatin or DNP-BSA but not by soluble gelatin or bovine serum albumin (BSA). It was also inhibited by a polyvalent rabbit antimouse Ig. DNP-gelatin was detected on the surface of cells recovered from DNP-gelatin-coated dishes by 125-I-labeled anti-DNP Ig. The cell surface bound DNP-gelatin could be removed by treatment with collagenase. Collagenase treatment did not detectably affect cell viability or surface receptors. More than 90% of DNP-gelatin binding cells were labeled with a polyvalent 125-I-labeled antimouse Ig before or after collagenase treatment under conditions known to label B lymphocytes. Furthermore, the specific antigen-binding capacity of the purified cell populations could be demonstrated after treatment with collagenase. Purified DNP4-gelatin binding cells contained more than 100 times as many DNP-RFC than unfractionated cells. The enrichment of NIP-RFC in the cell population recovered from NIP3 gelatin-coated dishes was more than 200-fold.
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PMID:Separation of antigen-specific lymphocytes. I. Enrichment of antigen-binding cells. 4 91

Sputum was collected from patients with purulent chronic bronchitis. Immuno-chemical techniques using rabbit antiserum against human granulocyte collagenase and elastase showed the presence of both enzymes. Also the serum protease ingibitors alpha1-antitrypsin and alpha2-macroglobulin were demonstrated. Their protease inhibiting capacity was saturated. Granulocyte elastase and collagenase occurred not only in complexes with the inhibitors, but also as free enzymes. All sputa showed free proteolytic, elastolytic and collagenolytic activity. The concentration of collagenase was equal in the sol phase and in the gel phase of the sputa, but most of the elastase was bound to the gel phase.
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PMID:Granulocyte collagenase, elastase and plasma protease inhibitors in purulent sputum. 5 Feb 36

Rabbit antisera were produced against purified calf dermatosparatic procollagen and against the purified procollagens obtained from the culture medium of calf dermatosparatic cells. These antisera and their derived gamma-globulins were characterized by immunoprecipitation, double immunodiffusion and immunoelectrophoresis. Antiserum directed against dermatosparatic procollagen cross-reacted with the two different forms of procollagen obtained from the culture medium of dermatosparatic calf cells. Antiserum directed against onw of these procollagens, namely (pro alpha1)2 pro alpha2, cross reacted with dermatosparatic procollagen and also cross-reacted with the other procollagen,(pro alpha1)3. Antiserum directed against procollagen (pro alpha1)3 cross-reacted with dermatosparatic procollagen and with the procollagen (pro alpha1)2 pro alpha2. None of the antisera reacted with authentic calf skin collagen, or with the collagen extracted from the cell layer of the dermatosparatic calf cells in culture. Reduction andalkylation of the procollagens abolished the antigen-antibody reactions, while prior digestion of the antigens with bacterial collagenase did not eliminate the immunological reaction. Antigenic determinants in the cell culture procollagens were found at the COOH-terminal non-collagen peptide as well as at the NH2-terminal non-collagen peptide.
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PMID:Immunological properties of procollagens obtained from the culture medium of dermatosparactic cells. 5 Feb 85

It is apparent that significant progress has been made in our understanding of the biosynthesis, modifications, and maturation of collagen and elastin. We now recognize and partially understand special reactions involved in hydroxylations within the cell and complex cross-linking processes occurring outside the cell. Recent experiments (191) have shown that in human diploid fibroblast cultures of limited doubling potential (191) the hydroxylation of collagen prolyl residues appears to be "age" or passage-level dependent. With increasing passage level of these cultures, both the ascorbate requirements and the extent of collagen hydroxylation decrease. "Young" cell cultures have a strong requirement for complete hydroxylation and without ascorbate there is only about 50% of the normal level. "Middle-aged" cultures show higher hydroxylation without and full hydroxylation with ascorbate, whereas "old" (or cultures close to "senescence") are incapable of full hydroxylation with or without ascorbic acid. Although the overall system may show some deterioration with increasing passage levels, it appears that with increasing passage levels other components in the cell replace the ascorbate dependence of the hydroxylase system to a greater exten. In some ways, aging WI-38 cultures begin to resemble some transformed cells in their biochemical reactions, although they continue to remain diploid and eventually lose the ability to replicate. It is not yet known whether old animals can produce collagen, which may now be underhydroxylated, perhaps contributing to certain senescent changes. Careful examination of the hydroxylation index of collagen produced in organoid cultures of tissue biopsies as a function of donor age might be informative, particularly if one looks at the quality of collagen by employing collagenase and other proteolytic digests with collagen (191). One could comare the levels of frequent and characteristic peptide triplet sequences such as Gly-Pro-Hyp to Gly-Pro-Pro, Gly-Ala-Hyp to Gly-Ala-Pro, or Gly-Pro-Hyl to Gly-Pro-Lys and others for evaluation of hydroxylation throughout the entire molecule or at selected sequences.
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PMID:Posttranslational protein modifications, with special attention to collagen and elastin. 5 Jun 3

Human leukocytes, when exposed to aggregated human gamma-globulin (AHGG) or immune complexes (isolated from RA synovial fluid) fixed to a cartilagenous surface, release neutral proteases that degrade the extracellular matrix of cartilage. The chondromucoprotein destruction by these proteases is suppressed by a variety of synovial fluids but is not susceptible to inhibition by trypsin, chymotrypsin, elastase inhibitors, or a combination of these agents. The inhibitory effect of synovial fluid can be reversed in the presence of increasing enzyme concentrations. Intact viable human polymorphonuclear leukocytes in the presence of AHGG also release a collagenase precursor that can be activated by limited proteolysis with trypsin or RA synovial fluids. Enzyme release (neutral proteases) by phagocytosing cells is inhibited by the antiinflammatory agents phenylbutazone and colchicine; these agents do not affect release of the collagenase precursor. However, the latent collagenase release is susceptible to inhibition when leukocytes are preincubated (prior to exposure to AHGG) with inhibitors of protein synthesis. Under these conditions, neutral protease release is unaffected.
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PMID:Connective tissue-degrading enzymes of human leukocytes. 5 2


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