Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The paper represents a summary of our studies in which in vitro perfusion of human and animal coronary vessels was carried out. Formation and uptake of lipids in perfused human coronary arteries were studied under a vairety of experimental conditions, including exposure to carbon monoxide. The effect of collagenase on lipid synthesis and transport in carotid arteries of dogs was also studied. Human plasma with hydrogen-3-labeled cholesterol and carbon-14-acetate was used to perfuse human blood vessels. Autologous plasma was employed. Inhibition of cholesterol uptake was accomplished by the addition of 7-ketocholesterol (concentrations of 0.005 to 1 mum/ml) to the perfusate. Both atherosclerotic and normal human coronary arteries incorporated 14C-acetate into lipids but failed to synthesize either cholesterol of cholesterol esters. Similar results were obtained in human saphenous veins perfused at arterial pressure. Cholesterol uptake from the perfusion fluid was demonstrated in atherosclerotic and normal human coronary arteries as well as in human saphenous veins. Carbon monoxide increased permeability of the arterial wall to cholesterol uptake. In dog arteries exposed to collagenase marked increases in cholesterol uptake were found, but total lipid synthesis was reduced; the relative synthesis individual lipids remained unchanged. The addition of 7-ketocholesterol to the perfusate reduced cholesterol uptake by the vessel by 90 percent. Inhibition of cholesterol uptake was present in all species and was not due to oxidation of cholesterol to 7-detocholesterol in the perfusate. The results illustrate that human coronary arteries as well as human saphenous veins synthesize lipids but not cholesterol. Cholesterol flux into the artery is augmented by carbon monoxide and collagenase. The data also show that active inhibition of cholesterol uptake in the arterial wall can be accomplished by competitive inhibition with 7-ketocholesterol.
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PMID:Lipid metabolism in perfused human and dog coronary arteries. 16 13

Bone morphogenetic activity is transmitted from the residue of a collagenase digest of bone matrix gelatin not only across cellulose acetate membranes but also through an interstitial fluid filled duplex diffusion chamber (a distance 300 + 2,000 mum). Collagenolysis enhances dissociation of the bone morphogenetic property of bone matrix and dissemination among mesenchymal cells proliferating in the host bed surrounding the diffusion chamber. The bone morphogenetic response is associated with secretion of interstitial fluid, enzymes, and fibrin as well as formation of new collagen fibrils beaded with coarse ruthenium red granules in the pores of the cellulose acetate membrane. Membranes with pore sizes too small to accommodate either new collagen fibrils or mesenchymal cell microvilli do not transmit the morphogenetic response.
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PMID:Diffusion of bone morphogenetic activity from the residue of collagenase digested bone matrix gelatin through interstitial fluid. 17 84

Specific collagenase from the culture media of various rabbit tissues and cells exists in active and latent forms. Latent collagenase is most effectively activated with 4-aminophenylmercuric acetate, a thiol-blocking reagent, strongly suggesting that latent forms are enzyme-inhibitor complexes. A collagenase inhibitor from bone cultures, which may be closely related to the inhibitor of such latent enzyme complexes, was partially characterized.
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PMID:Evidence that latent collagenases are enzyme-inhibitor complexes. 19 84

As tissue cultures, rabbit bone, skin and non-gravid uterus synthesise inhibitors of collagenase (EC 3.4.24.3). An assay for the inhibitors is described and their action on collagenase from different tissue sources demonstrated. Evidence for the involvement of the tissue inhibitors of collagenase in the latency of the enzyme in culture media is presented. Latent collagenase was activated by treatment with 4-aminophenylmercuric acetate, and then reacted with the inhibitors to form inactive complexes with properties similar to the naturally occurring latent enzyme forms. The associated changes in molecular weight are detailed, and discussed in relation to the observations of other workers concerning the extracellular control of collagenase activity.
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PMID:The detection and characterisation of collagenase inhibitors from rabbit tissues in culture. 19 53

Bone explants from foetal and newborn rabbits synthesize and release a collagenase inhibitor into culture media. Inhibitor production in the early days of culture is followed first by latent collagenase and subsequently active collagenase in the culture media. A reciprocal relationship exists between the amounts of free inhibitor and latent collagenase in culture media, suggesting strongly that the inhibitor is a component of the latent form of the enzyme. Over 90% of the inhibitory activity of culture media is associated with a fraction of apparent mol.wt. 30000 when determined by gel filtration on Ultrogel AcA 44. The inhibitor blocks the action of rabbit collagenase on both reconstituted collagen fibrils and collagen in solution. It inhibits the action of either active collagenase or latent collagenase activated by 4-aminophenylmercuric acetate. Latent collagenase activated by trypsin is usually much less susceptible to inhibition. The activity of the inhibitor is destroyed by heat, by incubation with either trypsin or chymotrypsin and by 4-aminophenylmercuric acetate. Collagenase activity can be recovered from complexes of enzyme (activated with 4-aminophenylmercuric acetate) with free inhibitor by incubation with either trypsin or 4-aminophenylmercuric acetate, at concentrations similar to those that activate latent collagenase from culture media. The rabbit bone inhibitor does not affect the activity of bacterial collagenase, but blocks the action of collagenases not only from a variety of rabbit tissues but also from other mammalian species.
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PMID:Identification and partial characterization of an inhibitor of collagenase from rabbit bone. 20 52

Rabbit bones in culture produce specific collagenase and neutral metallo-proteinase activity in latent forms that can be activated by either 4-aminophenylmercuric acetate or trypsin. Latent neutral metallo-proteinase activity was resolved by gel filtration into two enzymes, distinct from collagenase, that degrade gelatin and cartilage proteoglycans.
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PMID:Neutral metallo-proteinases of rabbit bone. Separation in latent forms of distinct enzymes that when activated degrade collagen, gelatin and proteoglycans. 20 63

The effect of the potent tumor promoter phorbol 12-myristate 13-acetate (PMA) on collagen synthesis, a differentiated property of chick embryo fibroblasts, was examined. Collagen synthesis, as measured by the rate of formation of [3H]hydroxyproline from [3H]proline, was found to be decreased in cells treated with PMA but not in cells treated with the parent alcohol phorbol. The decrease in collagenase-sensitive proteins was confirmed by polyacrylamide gel electrophoresis of cell lysates, indicating that the decrease could not be ascribed simply to an effect on prolyl hydroxylase. Although a decrease in collagen synthesis was observed after one day, five days were required for a maximal reduction to 20% of that of dimethyl sulfoxide-treated controls. The effect of PMA on collagen synthesis was reversible. It was therefore not the result of a permanent transformation of the cells or of the selection of a population of cells with a reduced capacity for collagen synthesis. Collagen synthesis was decreased in chick embryo fibroblasts transformed by Rous sarcoma virus. Treatment of these cells with PMA for 5 days brought about a further decrease to 50% of the level in dimethyl sulfoxide-treated transformed controls.
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PMID:Decrease in collagen production in normal and Rous sarcoma virus-transformed chick embryo fibroblasts induced by phorbol myristate acetate. 21 32

A series of intracellular events occurring after treatment of rabbit synovial fibroblasts with 0.01 micrograms/ml phorbol myristate acetate (PMA) were measured. Ten minutes after addition of PMA, there was a temporary increase in intracellular cyclic AMP levels, followed by a transient decrease in incorporation of 3H-thymidine into DNA. Approximately 500 ng/mg cell protein of PGE2 were found in culture medium from the 12- to 24-hour incubation period, but significant collagenase was not detectable until 24 to 36 hours. Treatment with aspirin or indomethacin abolished PGE2 production but did not affect collagenase levels. Production of enzyme was associated with a cessation of cell proliferation, measured by protein content/culture and cell number. No enzyme was detectable in untreated cultures. Synovial fibroblasts treated with phorbol myristate acetate may provide a good model for studies on the mechanism of induction of collagenase production.
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PMID:Collagenase production by synovial fibroblasts treated with phorbol myristate acetate. 22 97

1. Pig synovium in tissue culture secretes a specific collagenase in a latent form. 2. The latent enzyme was concentrated by (NH4)2SO4 precipitation and activated with 4-aminophenylmercuric acetate, and the active enzyme was purified by chromatography on Ultrogel AcA44, DEAE-cellulose, heparin-Sepharose and a zinc-chelate medium to a specific activity of 53 400 units/mg. of protein. 3. The enzyme was shown to be essentially homogeneous by polyacrylamide-gel electrophoresis. 4. The purified collagenase digested collagen to give the characteristic three-quarter and one-quarter pieces.
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PMID:Purification of pig synovial collagenase to high specific activity. 23 70

A procedure was developed for the isolation of intact islets of Langerhans from sheep pancreas. The pancreas was disrupted by syringe injection of Hanks solution followed by collagenase incubation and islet separation by sedimentation. The islets were incubated in varying concentrations of glucose and butyrate. The rate of insulin release was approximately linear while the glucose and butyrate concentrations were increased. In additional studies at 2.5 and 5.0 mM levels of substrate concentration, the stimulation of insulin had the following pattern: octanoate greater than hexanoate greater than butyrate, whereas beta-hydroxybutyrate, lactate, acetate, and propionate had only slight stimulatory effects that were not statistically significant. Decanoate did not alter insulin release from isolated islets. These data confirm earlier in vivo reports that fatty acids stimulate pancreatic hormone release in sheep and that the stimulus is related to chain length of the fatty acid through C-8 but that C-10 has no effect. A hypothesis was suggested to explain these results based on chain length, solubility, and plasma membrane alterations.
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PMID:Effect of fatty acids on isolated ovine pancreatic islets. 34 24


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