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 collagenase was purified from homogenates of V2 ascites-cell carcinoma growing in rabbit muscle. (NH4)2SO4 precipitation, ion-exchange and gel-filtration chromatography, and affinity chromatography (by using the CB7 CNBr) cleavage fragment of alpha 1(I) collagen linked to agarose) gave a 268000-fold purification and a sevenfold increase in total enzyme units recovered. The specific activity, defined as mumol of collagen in solution cleaved/h per mg of enzyme at 35 degrees C, WAS 1.74.2. The collagenase had a broad pH optimum from pH7.0 to 9.5, and a mol.wt. of between 33000 and 35000. It was inhibited by dithiothreitol, L-cysteine, D-penicillamine, EDTA and 1,10-phenanthroline, and by both rabbit and human serum. 3. Removal of cations by a chelating resin (Chelex 100) produced as inactive enzyme that could be reactiviated by the addition of Ca2+ ions at concentrations as low as 1muM. Other bivalent cations were not effective. 4. The purified collagenase cleaved peptides alpha2 and alpha1-CB7 (denatured polypeptides of collagen) at 37 degrees C at one site only. [alpha1 (I)]2alpha2 and [alpha1(III)]3 collagens in solution were cleaved at the same site approximately five times more rapidly than [alpha1 (II)]3. 5. An inhibitor of the enzyme in the tumour extracts, which was dissociable from the enzyme at the (NH4) 2SO4 precipitation step of purification, had a mol. wt. of between 40000 and 50000 but was distinct from the alpha1 trypsin inhibitor. 6. Studies with zonal density-gradient centrifugation suggested that the enzyme was bound to fibrillar substrate (collagen) extracellularly, but that it was not associated with enzymes originating in cell mitochondria, microsomal preparations or lysosomes.
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PMID:Purification and characterization of a collagenase extracted from rabbit tumours. 0 61

The binding of Ca2+ to a salivary phosphoprotein, protein C, was studied by equilibrium dialysis. In 5mM-Tris/HCl buffer, pH 7.5, protein C bound 190 nmol of Ca2+/mg of protein. The apparent dissociation constant, K, was determined to be 1.9 x 10(-4)M and the binding of Ca2+ to the protein was non-co-operative. The binding of Ca2+ to protein C apparently depends on groups which ionize above pH 5.0. Ca2+ binding decreased with increased concentration of the dialysis buffer and on addition of SrCL2, MgCl2 and MnCl2 to the dialysis buffer. Digestion of protein C with trypsin or collagenase or heating of the protein to 60 degrees or 100 degrees C had little or no effect on the Ca2+ binding. Digestion of protein C with alkaline phosphatase caused a decrease in the amount of protein-bound Ca2+. This was also found for another salivary phosphoprotein, protein A. In the absence of Ca2+ the S020,w for protein C was 1.29 S and in the presence of Ca2+ it was 1.46S. Ca2+ may cause a conformational change in the protein or an aggregation of the protein molecules. No conformational changes of protein C in the presence of Ca2+ could be detected by circular dichroism or nuclear magnetic resonance.
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PMID:The binding of calcium to a salivary phosphoprotein, protein C, and comparison with calcium binding to protein A, a related salivary phosphoprotein. 1 96

PZ-peptidase is an endopeptidase that cleaves the synthetic substrate developed for clostridial collagenase, 4-phenylazobenzyloxycarbonyl-L-Pro-L-Leu-Gly-L-Pro-D-Arg (PZ-peptide). The peptidase has been purified to homogeneity from chicken embryos. The enzyme has a pH optimum of 7.5 to 8.5, and isoelectric point of 5.0, and a molecular weight of 77,000. The kinetic parameters at pH 8 and 37 degrees are: Km = 2 X 10(-4) M and Vmax = 4.2 mumol/min/mg of protein. The enzyme is inhibited by p-hydroxymercuribenzoate (100%), N-ethylmaleimide (60%), and chelating agents (40 to 60%). Maximum activity is attained in the presence of reducing agents and Ca2+, Sr2+, or Mg2+. The peptidase has no detectable action on casein, serum albumin, collagen, collagen alpha chains, various collagen peptides (alpha1)(I)-CB2, alpha1(I)-CB3, alpha1(I)-CB4), (Gly-Pro-Pro)10, or (Gly-Pro-Pro)5. It does catalyze the hydrolysis of the Hyp--Gly bond in the 17-residue collagen peptide alpha1(II)-CB6-C2 and it partially digested a mixture of collagen peptides of molecular weight 350 to 2500. A role of this peptidase in collagen breakdown appears to be restricted to a late stage when degradation products would fall in the range of 5 to 30 residues.
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PMID:PZ-peptidase from chick embryos. Purification, properties, and action on collagen peptides. 1 6

The effects of metabolic and respiratory acidosis and alkalosis on cellular calcium metabolism were studied in rat kidney cells dispersed with collagenase. In both types of acidosis, the intracellular pH, total cell calcium, and the cell relative radioactivity after 60 min of labeling are significantly depressed. Kinetic analysis of 45-ca desaturation curves shows that acidosis decreases all three cellular calcium pools and depresses calcium fluxes between the superficial and cytosolic pools and between the cytosolic and mitochondrial pools. In alkalosis the intracellular pH, the total cell calcium, and the cell relative radioactivity are significantly increased. Kinetic studies show that in alkalosis, only the mitochondrial pool is consistently increased. Calcium exchange between the mitochondrial and cytosolic pool is increased in metabolic alkalosis only. These results suggest that hydrogen ion is an important modulator of calcium metabolism, and that the intracellular pH rather than extracellular pH is the critical factor in determining the calcium status of cells during altered acid-base conditions.
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PMID:Effect of pH on the calcium metabolism of isolated rat kidney cells. 4 33

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

Isolated gastric smooth muscle cells were prepared from the stomach of Bufo marinus by successive incubation in collagenase without added trypsin. Contraction was determined by image-splitting micrometry and expressed as the mean percentage decrease in cell length from control. Peak contractile response was attained within 30 s. Dose-response curves constructed from peak responses showed that the maximal responses to CCK-OP (37.2 +/- 3.8%), acetylcholine (35.3 +/- 2.5%), and Ca2+ (42.3 +/- 0.9%) were similar. The D50s for octapeptide of cholecystokinin (CCK-OP) and acetylcholine were around 10(-12) M and 10(-11) M, respectively. The response to a combination of submaximal concentrations of acetylcholine and CCK-OP exceeded the individual responses but did not exceed the maximal response to either agent alone. A low concentration of atropine (5 X 10(-10) M) inhibited specifically the maximal response to acetylcholine. A high concentration of atropine (5 X 10(-8) M) inhibited partially the maximal response to CCK-OP but had no effect on the maximal response to Ca2+. It was concluded that 1) dispersed gastric smooth muscle cells are highly sensitive to stimulation; 2) CCK-OP has a direct (myogenic) contractile effect on gastric smooth muscle; and 3) the effect of CCK-OP and acetylcholine are mediated by separate receptors.
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PMID:Interaction of acetylcholine and cholecystokinin with dispersed smooth muscle cells. 11 64

The epithelium of the urinary bladder of Bufo marinus is composed of 5 cell types, i.e., granular (Gr), mitochondria-rich (MR) and goblet (G) cells which face the urinary lumen, microfilament-rich (MFR) and undifferentiated cells (Un) located basally. The epithelium was dissociated by collagenase and EGTA treatment. Fractionation of dispersed cells by isopycnic centrifugation on dense serum albumin solutions yielded 4 fractions: (i) a very light fraction (p approximately equal to 1.025) enriched in MR and MFR cells; (ii) a light fraction (p approximately equal to 1.045) enriched in vacuolated Gr cells; (iii) a heavy fraction (p approximately equal to 1.065) composed essentially of aggregated Gr cells, and (iv) a pellet (p approximately equal to 1.085) enriched in G and undifferentiated cells. Recoveries were based on cell counts and DNA measurements. DNA content per cell was 13.2 pg +/- 0.9 (n = 37). From 1 g fresh tissue, 62 +/- 5 x 10(6) (n = 10) cells were recovered before isopycnic centrifugation of which about 70% excluded Trypan blue. After centrifugation, 90 to 95% of the cells excluded the vital dye and approximately 3(9) x 10(6) cells were recovered from the gradient. Cell metabolism in each fraction was estimated by oxygen consumption measurements in absence or presence of ouabain, acetazolamide, and dinitrophenol. The consumption measurements in absence or presence of ouabain, acetazolamide, and dinitrophenol. The consumption was threefold higher in the very light and light fractions when compared to the heavy and pellet fractions. Ouabain sensitive oxygen consumption (QO2) represented 12 to 35% of the total O2 consumption depending on the cell fraction, and acetazolamide sensitive QO2 varied from -0.8% in the heavy fractions to 20% in the lighter fractions. DNP increased QO2 in all fractions by 20 to 50%. Finally, the cells were able to reaggregate and form junctional complexes upon addition of calcium to the medium.
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PMID:Isolation and separation of toad bladder epithelial cells. 11 48

Adult rat heart was dissociated into a single cell suspension by a perfusion technique which used 0.05% collagenase and 0.1% hyaluronidase in Krebs-Ringer phosphate buffer (KRP). The non-muscle cells of the suspension were separated from the myocytes by centrifugation through 3% Ficoll solution in KRP with 0.01 mM Ca2+. An approximately 90% pure suspension of isolated single muscle cells was obtained with this method. The effects of the successive steps in the dissociation procedure on the ultrastructure of the heart were studied by scanning and transmission electron microscopy. After 30 minutes of enzyme digestion, dissociation of the inner endothelial lining of the ventricle into single cells or small groups of cells became apparent. In addition, the underlying cardiac skeleton began to disintegrate and linear arrays of cardiac muscle cells were observed. After 45 minutes of enzyme digestion the number of released single cells was higher because of the separation of intercalated discs. The majority of non-muscle cells were by now dissociated from the surfaces of muscle cells. Widening of the lateral intercellular spaces between the myocardial cells was associated with separation of desmosomes. In some regions of the heart, intact desmosomes, fasciae adherentes and gap junctions were observed even though lateral intercellular spaces had widened greatly. The majority of myocardial cells had become separated from one another after 60 minutes of enzyme digestion. Separation of gap junctional sites took place in two ways: (1) by 'unzipping' them through enzyme action; (2) by tearing them mechanically. Gap junction remnants were sometimes observed in a vesiculated state within the cell. The dissociation of the heart was ineffective when perfused with media containing 1.0 or 2 mM Ca2+. Alcian blue treatment after 60 minutes of enzyme digestion revealed that the basement membrane, and its accompanying collagen fibrils, was still present on the plasma membrane of dissociated single cells. The isolated myocardial cells retained their normal morphological characteristics. This study has enabled us to understand in detail how dismantlement of highly ordered adult cardiac tissue into a single cell suspension takes place. Cell suspensions of this type should be invaluable in the study of metabolic and synthetic activities in adult myocardial cells.
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PMID:Dissociation of adult mammalian heart into single cell suspension: an ultrastructural study. 12 Mar 52

To investigate the dystrophic influence on the characteristics of actin, a method for the isolation of F-actin filaments from the skeletal muscle of small sizes, i.e., less than 0.5 g, was devised. In this method, minced muscle was treated with collagenase and hyaluronidase, and the isolated filaments were washed with adenosine triphosphate (ATP). Upon examination in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the ATP-washed filaments showed a protein component identical in mobility to actin in untreated myofibrils or to that prepared by the conventional method. Electron microscopic appearances of the filaments were similar to those of F-actin filaments described in the literature. The dimensions of the filaments were 0.5--2.5 micrometer in length and 60--70 A in diameter. The ability to activate the Mg-adenosine triphosphatase or myosin was found to be Ca2+ independent. In all aspects of the above characteristics, the filaments from leg muscles of 129/Re dydy dystrophic mice and their litter mates were observed to be identical.
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PMID:Isolation of F-actin filaments. Comparison of F-actin filament preparations from normal and dystrophic mouse muscle. 15 92

Elucidation of the role of Ca2+ in the secretion of insulin and glucagon is complicated by the presence of different types of cells in the pancreatic islets. Visualization of calcium in sections of guinea pig pancreas with the histochemical reagent glyoxal bis-2-hydroxyanil revealed the most intense staining in the endocrine part but no differences between various islet cell types. A procedure for eliminating the majority of the beta-cells by streptozotocin injection in the guinea pig enabled a comparison of collagenase-isolated islets rich in alpha 2-cells with islets from untreated animals rich in beta-cells. The latter islets contained 24.6 +/- 2.4 mmol calcium/kg dry wt, as estimated by flameless atomic absorption spectrophotometry. This is twice as much as noted for the exocrine pancreas or the islets rich in alpha 2-cells. After storage for 3 days in culture medium, the two types of islets contained similar amounts of calcium. The cultured islets displayed differences related to cellular composition when measuring the incorporation of 45Ca into a lanthanum-nondisplaceable (intracellular) pool. In the presence of 3 mM glucose, more 45Ca was incorporated into the islets rich in alpha 2-cells. Increasing the glucose concentration to 20 mM with or without further addition of 30 U/liter bovine insulin was without effect on the 45Ca uptake into the islets rich in alpha 2-cells but stimulated that into islets rich in beta-cells. The different calcium dependence on glucose in the two types of islets may indicate that increased uptake of Ca2+ is a component of the mechanism for the secretion of both insulin and glucagon.
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PMID:Evidence for divergent glucose effects on calcium metabolism in pancreatic beta- and alpha 2-cells. 15 70


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