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)

The specificity of lactoperoxidase-catalyzed iodination for the proteins of the hepatoma tissue culture cell plasma membrane was examined by histochemical, biochemical, and cell fractionation techniques. Light microscope autoradiography of sectioned cells shows the incorporated label to be localized primarily at the periphery of the cell. Most of this label can be released from the cell by trypsin but not by collagenase or hyaluronidase. The label is recovered from the cells as either monoiodotyrosine or diiodotyrosine after hydrolysis of cell extracts with a mixture of proteolytic enzymes. The label co-purifies during cell fractionation with an authentic liver cell plasma membrane marker enzyme, 5'-nucleotidase. Thus, the incorporated iodide is itself a valid marker for those membrane polypeptides having tyrosine residues accessible to the lactoperoxidase. The polypeptide complexity of the purified plasma membrane was examined by high resolution dodecyl sulfate-polyacrylamide gel electrophoresis. At least 50 polypeptides in the membrane are accessible to iodination. These polypeptides probably represent the bulk of the protein mass of the membrane and iodinating them does not affect cell viability, growth rate, or cell function. Labeling experiments with fucose and glucosamine show that at least nine of the iodinated peptides may be glycoproteins.
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PMID:Proteins of the hepatoma tissue culture cell plasma membrane. 0 57

The relationship between activation of resting chick embryo fibroblasts by proteases and proteolytic alteration of the cell surface has been investigated. Five different proteases were examined: trypsin, collagenase, plasmin, alpha-chymotrypsin, and thrombin. All of these proteases, when added to the culture medium at concentrations of 0.08-2.2 mug/ml, stimulated deoxyglucose uptake and induced cell division. The absolute levels of stimulation depended on the specific protease. Activation ranged from a doubling in cell number in 24 hr for trypsin and thrombin down to a 47% increase in cell number for alpha-chymotrypsin. Except in the case of thrombin, the stimulatory effects of these proteases correlated with breakdown of Z, a protein which is the major chick surface protein as revealed by lactoperoxidase-catalyzed iodination and which disappears upon transformation. In the case of thrombin, stimulatory concentrations brought about no detectable loss of surface components. Thus loss of Z is not a necessary condition for activation of chick fibroblasts; it may be a sufficient condition for activation of part of the cell population.
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PMID:Effect of proteases on activation of resting chick embryo fibroblasts and on cell surface proteins. 17 Oct 80

Human erythrocytes, porcine and rat liver cells, porcine spleen lymphocytes and cultured human lymphoma cells (266 Bl) have been labelled with 125I by the lactoperoxidase-H2O2 method. Large amounts of radioactivity were released when the iodinated cells were incubated in different buffers, and the rate of the release varied considerably between the different cells. Incubation at a higher temperature increased the release rate, while metabolic inhibitors such as iodoacetamide, trasylol or sodium azide did not. When collagenase was used during the preparation of spleen lymphocytes, the rate of the radioactivity release was decreased about 50%. Several findings indicated that the released radioactivity originated from free iodide. When the labelled lymphocytes were treated with a nonionic detergent, Nonidet P-40, 90% of the total radioactivity was solubilized. Only 10-15% of the radioactivity was stably bound in macromolecular material. The remaining part, corresponding to the amount of radioactivity released during incubation, was shown to be free iodide. It is concluded that the significance of the 125I-label in living cells has to be studied in each case at the specific experimental conditions used. After the unspecifically trapped iodide is released--normally after about 2 h--the label is considered to be useful for studies with intact cells.
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PMID:The significance of 125I as a tracer for lymphocytes, liver cells and erythrocytes after iodination by the lactoperoxidase-H2O2 technique. 78 77

An oral periodontopathic bacterium, Bacillus cereus, was inhibited both by lactoperoxidase (LP) and myeloperoxidase (MP) antimicrobial systems. With the LP-SCN--H2O2 system, the growth inhibition was directly proportional to the amount of OSCN- ions present. The OSCN-, which is the principal oxidation product of the LP (or MP)-SCN--H2O2 system at neutral pH, is a normal component of human saliva. The oxidation products of both peroxidase systems inhibited the growth of the bacteria. This inhibition was associated with reduced extracellular release of collagenase activity from the cells. With LP, the antimicrobial efficiency of the oxidizable substrates was SCN- greater than I-, and with MP, the efficiency was I- greater than Cl- greater than SCN-, respectively. LP did not oxidize Cl-.
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PMID:Antibacterial effect of lactoperoxidase and myeloperoxidase against Bacillus cereus. 298 83

Two monoclonal antibodies that cause changes in the morphology of cultured chick myogenic cells have been described previously [8]. In this paper, these antibodies are shown to interact with the same 140Kd protein. The 140Kd protein has been further characterized as a cell-surface glycoprotein by lactoperoxidase-catalyzed iodinations and lectin affinity chromatography. The protein is resistant to digestion by trypsin and collagenase and has been shown to be unrelated to fibronectin by immunoprecipitation studies and by peptide mapping. A second protein, of approximately 170Kd MW, is also immunoprecipitated by the monoclonal antibodies. This protein is probably unrelated to the 140Kd protein since the peptide maps are quite distinct.
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PMID:Characterization of a 140Kd cell surface glycoprotein involved in myoblast adhesion. 638 44

The extracellular matrix of cultured chicken embryo fibroblasts undergoes a number of modifications during the early stages of oncogenic transformation. One alteration is increased production of a small protein (Mr approximately 21,000) which is transiently deposited in the matrix by transforming cells infected with LA24, a temperature-sensitive mutant of Rous sarcoma virus (RSV) (Blenis, J., and Hawkes, S.P. (1983) Proc. Natl. Acad. Sci. U.S.A. 80, 770-774). This protein is a major component of substratum-associated material (material which remains attached to culture dishes after removal of cells with ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid). Its synthesis is stimulated by transformation of cells with NY68, another ts mutant of RSV, and also by treatment of normal, uninfected cells with the tumor promoter, phorbol myristate acetate. Accessibility of the 21-kDa protein to lactoperoxidase-catalyzed iodination indicates an exposed location within the matrix. The protein binds strongly to the culture dish and/or other matrix components. This interaction can be disrupted by sodium dodecyl sulfate but not by several nonionic detergents, unless beta-mercaptoethanol or KCl (0.5 M) are also present. High concentrations of urea or guanidine hydrochloride also remove the protein from the matrix. The 21-kDa protein is resistant to trypsin, collagenase, and the hydrolytic enzymes associated with cells transformed by the wild-type Prague A RSV but not to Pronase or chymotrypsin. A 21-kDa protein with properties similar to those described above is also detected in the medium and binds to the matrix, suggesting that a potential route of deposition of the 21-kDa protein in the matrix may be via shedding and subsequent interaction with other matrix components.
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PMID:Characterization of a transformation-sensitive protein in the extracellular matrix of chicken embryo fibroblasts. 643 99

Collagen and its high-molecular-weight fragments specifically induce an extracellular collagenase (EC 3.4.24.8) in the Gram-negative Achromobacter iophagus. During the induction process the inducer is concentrated on the bacterial outer membrane. Two-dimensional electrophoresis of 125I-labelled outer membrane proteins has shown that, in particular, the amount of one protein which is already present on the surface of non-induced bacteria increases quantitatively when the inducer is added. After 125I-labelling of the cell membrane and its solubilization, the same protein is retained selectively on a gelatin-Sepharose column. It has isoelectric point of 4.9-5.1 and molecular weight of 40000. This molecular weight is close to that of the 35000 of the collagenase subunit. However, their non-identity was proved in three independent ways: upon two-dimensional electrophoresis, only those proteins in the range corresponding to the collagenase dimer (Mr 70000-80000) react with fluorescent anticollagenase antibody system, whereas the spot of the collagen-binding protein (mr 40000) is negative; the solubilized collagen-binding protein is not retained by anticollagenase-Sepharose affinity chromatography; in vivo, it is not protected by anti-collagenase antibodies against lactoperoxidase iodination. A hypothesis for the possible role of the collagen-binding protein in the induction of collagenase is proposed.
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PMID:Cell-surface collagen-binding protein in the procaryote Achromobacter iophagus. 682 47

The iodination of insulin was accomplished by a modification of the lactoperoxidase method. The use of a low concentration of hydrogen peroxide (1.5 ng/ul) followed by Sephadex gel filtration and purification on a cellulose column yielded iodoinsulin with an activity equal to that of native insulin in stimulation of glucose oxidation in rat epididymal fat cells and with high specific binding to collagenase-dissociated mouse mammary cells from pregnant and lactating mice. Other hormones tested did not displace the binding. Analysis of displacement curves and scatchard plots suggests that both the affinity and the number of sites for insulin binding differ between pregnant and lactating mammary cells.
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PMID:A method for the iodination of insulin and its binding to dissociated mouse mammary cells. 701 91