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

---

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

Hepatocytes isolated from the liver of the common goldfish Carassius auratus L. with crude bacterial collagenase maintained ATP levels for at least 2 h. Glycogenolysis was maximally activated by 1 X 10(-6) M epinephrine and 5.8 X 10(-9) M glucagon. In liver cells incubated in calcium-free buffer containing 1 mM ethylene glycol-bis-(beta-aminoethylether)-N,N'-tetraacetic acid, basal glycogenolysis was enhanced by the addition of 1-4 mM calcium but the elevation of cyclic AMP and glycogenolysis due to epinephrine was unaffected by calcium. The divalent cation ionophore A23187 did not alter basal or hormone-stimulated glycogenolysis. Isoproterenol was approximately as potent as epinephrine but phenylephrine was glycogenolytic only at very high concentrations. l-Propranolol competitively inhibited the increased glycogenolysis due to catecholamines but phentolamine was ineffective as a blocking agent. Isoproterenol and epinephrine stimulated glycogenolysis at lower concentrations than those required to elevate cyclic AMP accumulation. Phenylephrine was without effect on cyclic AMP. Propranolol competitively inhibited both epinephrine- and isoproterenol-stimulated cyclic AMP accumulation, but phentolamine did not block either response. Catecholamine-stimulated glycogenolysis in goldfish liver is apparently a beta-adrenergic effect. However, low concentrations of epinephrine enhance glycogenolysis without affecting total cyclic AMP.
...
PMID:Hormone-stimulated glycogenolysis in isolated goldfish hepatocytes. 18 9

A bone morphogenetic protein (BMP) obtained in solution by digestion of demineralized rabbit cortical bone matrix with bacterial collagenase retains its biologically active conformation in a neutral salt/ethylene glycol mixture. BMP may be insolubilized by coprecipitation with calcium phosphate and resolubilized by chemical extraction with a neutral salt in the same solvent mixture. Upon concanavalin A-Sepharose chromatography, BMP is bound by hydrophobic interaction and carbohydrate recognition and is recovered by elution with either alpha-methyl mannoside or ethylene glycol solvent mixture. Implants of both eluates and the extracts of the coprecipitate in double-walled diffusion chambers induce transmembrane bone morphogenesis. BMP is not species specific; rabbit BMP induces new bone formation in the rat. The present observations indicate that BMP is a glycoprotein.
...
PMID:Solubilized and insolubilized bone morphogenetic protein. 22 8

Pancreatic islets from C57BL/KsJ-db/db, and +/+ mice were isolated by collagenase. After isolation the islets were transferred to a hypotonic ethidiumbromide solution with 0.3% of the detergent Nonidet P40. After vortexing, the samples were analyzed in a BioPhysics Cytofluorograf 4802A. The DNA histograms were divided into 2c, 2-4c, 4c and 8c fractions under the assumption of a constant rate of DNA synthesis during the 2-4c phase. In comparison with normal mice, we found that diabetic mice had a lower fraction of 2c nuclei and a higher fraction of 2-4c, 4c, and 8c nuclei. These results obtained by flow cytometry are in agreement with results obtained by 3HTdR incorporation and by cytophotometry on histological sections.
...
PMID:Flowcytometric evaluation of the DNA distribution in isolated pancreatic islets from normal and diabetic mice. 37 3

Methods have been detailed to prepare a crude membrane fraction from isolated porcine adipose tissue cells. Adipocytes were obtained after incubation of 5 g of adipose tissue slices with 4,500 units of a selected lot of collagenase in a total volume of 15 mL at 37 degrees C for 90 min. There was no bovine serum albumin present during cell isolation because albumin did not enhance cell yield or yield of lipolytic activity. Isolated cells were lysed by exposure to hypotonic conditions in the presence of 7.5 mM ethylene glycol tetraacetic acid (EGTA) and .8 mM phenylmethylsulfonyl fluoride (PMSF). A 30,000 x g centrifugal pellet was used as the crude membrane preparation. Binding of tritiated dihydroalprenolol (DHA), a beta-adrenergic antagonist, was measured in the presence of 7.5 mM EGTA and .2 mM PMSF, because these protease inhibitors improved specific binding by approximately 50% to greater than 150 fmol/mg of protein and decreased non-specific binding to less than 10% at 2.5 nM DHA.
...
PMID:Beta-adrenergic receptor binding in crude porcine adipose tissue plasma membranes. 131 50

Many biotransformation activities have absolute or modulated localization within the hepatic acinus. To investigate the intrahepatic acinar zonation of vitamin D3 (D3) metabolism, hepatic D3 extraction was investigated by antegrade or retrograde perfusion of normal livers and livers bearing selective periportal (PP) or perivenous (PV) destruction; D3 C-25 hydroxylation was studied after selective harvesting of PP or PV hepatocytes by digitonin-collagenase perfusion. Data indicate that hepatic D3 extraction is not regioselective and not perturbed by destruction of the proximal (PP) or distal (PV) part of the acinus, indicating that D3 extraction takes place in the most proximal hepatocytes being perfused. These observations suggest that, in vivo, D3 extraction will take place according to its concentration gradient within the hepatic acinus, thus resulting in a preferential PP extraction of the vitamin. D3 C-25 hydroxylation was higher in PP than in PV hepatocytes in the presence of 1.9 mM Ca2+, with 25-hydroxyvitamin D3 [25(OH)D3] formation of 34.6 +/- 3.9 and 24.4 +/- 1.1 fmol.h-1.(10(6) hepatocytes)-1, respectively (P less than 0.05). Modulators of extracellular [ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA)] or intracellular Ca2+ (parathyroid hormone, A23187), however, significantly influenced 25(OH)D3 formation with similar decreases in the PP (31%) and PV (26%) areas in the presence of EGTA but with increases in the presence of Ca2+ ionophore A23187 of 189 +/- 16% in PP and of 260 +/- 20% in PV hepatocytes, resulting in similar production in both regions of the acinus.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:C-25 hydroxylation of vitamin D3 in periportal and perivenous region of hepatic acinus. 131 77

1. Carotid body chemoreceptors were removed intact from adult rats and subjected to protease and collagenase enzymatic digestion of connective tissue. 2. Recordings from the sinus nerve demonstrated that chemotransduction remains intact for at least 2-3 h after isolation, enzyme exposure, and suspension in N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES)-buffered saline at room PO2. 3. After mechanical dissociation, the interrelationship between changes in extracellular PO2 and pH and relative changes in intracellular calcium (Ca2+i) were observed in glomus cells with the use of fluo-3 and confocal microscopy. 4. Brief (60-s) decreases in PO2 from 150 mmHg to near 0 mmHg, at nadir, caused a marked reduction in Ca2+i (peak delta F/F0 = -32 +/- 3%, mean +/- SE, n = 43), which rapidly recovered after reoxygenation. The decrease was reproducible from trial to trial and was also observed in HCO3(-)-buffered Ringer solution. 5. Superfusion with Ca(2+)-free HEPES saline with 1 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) blocked the hypoxia-induced increase in afferent chemoreceptor activity in vitro. Superfusion of the same solution over isolated cells for 15 min caused a large decrease in Ca2+i (-34 +/- 7%, n = 16). 6. In the presence of Ca(2+)-free HEPES, reoxygenation caused calcium fluorescence to increase. This suggests that the Ca2+ decrease during hypoxia is due, at least partially, to binding to an intracellular site. 7. Extracellular cobalt (1 mM, 15 min) also reversibly blocked the chemoreceptor response to hypoxia, in vitro, and caused a reduction in Ca2+i (delta F/F0 = -37 +/- 8%, n = 11).(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Hypoxia decreases intracellular calcium in adult rat carotid body glomus cells. 162 63

The C-terminal telopeptide of the alpha 1 chain of type I collagen from bovine skin was isolated from a bacterial collagenase digest. Two forms of the telopeptide were obtained, one with two and the other with three residues of tyrosine. In both of these, the single lysyl residue had been oxidized to alpha-aminoadipic delta-semialdehyde. Circular dichroism spectra of the telopeptide in aqueous solution at neutral pH were interpreted as indicating the presence of little regular secondary structure. However, sodium dodecyl sulfate at a concentration of 40 mM induced some alpha helix, as predicted from the sequence, and trifluoroethanol also induced secondary structure, probably a mixture of alpha helix and beta sheet. A major feature of the circular dichroism spectra of the telopeptide in sodium dodecyl sulfate, in denaturing agents, and in sodium phosphate buffer at low temperature was a positive band at 227 nm due to tyrosine side-chain chromophores. The disappearance of this band on heating and at high pH was ascribed to the adoption by the telopeptide of a specific tertiary structure. Poly(ethylene glycol) 1000 used as a perturbant in UV difference spectroscopy caused conformational changes resulting in decreased accessibility of tyrosine side chains and transfer of these to a less polar environment. A structural model in which the four aromatic side chains of the telopeptide are arranged in two pairs with the rings antiparallel is proposed to account for these results.
...
PMID:Spectroscopic study of environment-dependent changes in the conformation of the isolated carboxy-terminal telopeptide of type I collagen. 396 71

A neutral protease with a marked specificity for gelatin as a protein substrate has been purified to homogeneity from medium of human skin in serum-free explant culture. The pH optimum of this gelatinase is between 7.0 and 7.5 with little or no activity displayed below pH 5. Inhibition by EDTA, ethylene glycol bis(beta-amino-ethyl ether)N,N,N',N'-tetraacetic acid (EGTA), and 1,10-phenanthroline suggest that the enzyme is a metalloendopeptidase. Calcium concentration-dependent inhibition of the enzyme by EGTA and EDTA suggest further that there is a requirement for extrinsic calcium. Indeed, removal of calcium and reduces enzyme activity, and subsequent addition of calcium restores full activity. The gelatinase is not inhibited by serine protease inhibitors but is inhibited by cysteine, dithiothreitol, and beta-mercaptoethanol. It is also inhibited by a macromolecular inhibitor of collagenase which has been purified from human skin fibroblasts. The apparent molecular weight of this enzyme, as determined by gel filtration is 120,000-150,000. The enzyme is a glycoprotein, as indicated by staining with periodic acid-Schiff reagent and by its affinity for lectins. Human skin gelatinase shows little or no reactivity toward common protein substrates, such as hemoglobin or casein, and does not cleave helical collagen. Two sites of cleavage in the sequence of gelatin, Gly-Ile and Gly-Leu, have been positively identified using synthetic substrates and tryptic peptides of collagen.
...
PMID:Purification and properties of a gelatin-specific neutral protease from human skin. 626 Aug 9

Although there is good evidence for the presence of human neutrophil (PMN) collagenase, only moderate purification has been reported. The probable explanation for this fact is that most assays used to specifically measure collagenase activity are not reliable if high levels of several different proteases are also present in the assay mixture. The PMN granule is just such a concentrated mixture. Therefore, polyacrylamide gel electrophoresis was used to identify and quantitate the alpha 1 3/4 and alpha 2 3/4 cleavage products diagnostic for mammalian collagenase. White cells (85% PMN's) were lysed in 0.34 M sucrose and granules were obtained. The granules were lysed by sonication, and the lysate was chromatographed on a Sephadex G-200 column followed by a Trasylol-Sepharose 4B column. This procedure resulted in a 1350-fold purification and a yield of 75 micrograms of enzyme/unit of blood. The collagenase was inhibited by ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid but not by sulfhydryl or serine protease inhibitors. The preparation was free of elastase, which has been shown to cleave type III collagen into alpha 1 3/4 and alpha 1 1/4 pieces. The pI of collagenase was shown to be 4.7 by isoelectric focusing, and the enzyme lost activity below a pH of 6.5 if collagen was absent. Antiserum was produced by 100-micrograms injections of the purified collagenase into rabbits. Titers were measured by the enzyme-linked immunosorbent assay. For determination of the specificity, collagenase and PMN extract were isoelectrically focused and blotted onto nitrocellulose. The antibody recognized only one band of protein in the PMN extract, which comigrated with the purified collagenase.
...
PMID:Purification of human neutrophil collagenase and production of a monospecific antiserum. 629 51

The incorporation of methionine, lysine, and leucine into protein was studied in Ca2+-depleted and Ca2+-restored preparations of C-6 glial tumor cells in minimal medium. Although incorporation proceeded at linear rates in both preparations for more than 1 h and into the same spectrum of proteins, Ca2+-restored cells incorporated amino acid 5- to 10-fold more rapidly than Ca2+-depleted cells. Addition of approximately 200 microM Ca2+ in excess of chelator was required to achieve maximal rates of incorporation in Ca2+-depleted preparations. Stimulation by Ca2+ was rapid in onset (several minutes) and slowly reversible by chelator. Ca2+ was uniquely potent and specific among physiologically occurring cations in conferring such stimulation. Stimulation of amino acid incorporation by Ca2+ occurred over a broad range of pH and osmolarities and was facilitated by Mg2+. The effects of Ca2+ in stimulating amino acid incorporation were not traceable to changes in cAMP metabolism, amino acid uptake, protein catabolism, cell ATP or GTP content, or aminoacylation of transfer RNA. Actinomycin D (1 microgram/ml) did not block the stimulatory effects of Ca2+ although puromycin and cycloheximide did. The stimulatory effects of Ca2+ on protein synthesis were not restricted to C-6 in minimal medium. Protein synthesis was reduced by ethylene glycol bis(B-aminoethyl ether)-N,N,N',N'-tetraacetic acid 40 to 75% in C-6 glioma, GH3 pituitary tumor, PC-12 adrenal tumor, N2A neuroblastoma, and HeLa cells incubated under simulated growth conditions with various enriched media and sera. Ca2+-depleted S49 lymphoma, CHO ovarian tumor, and normal, dispersed chicken embryo cells in enriched medium responded to Ca2+ restoration with increased rates of protein synthesis as did collagenase-dispersed normal rat liver cells in minimal medium. Protein synthesis in rabbit reticulocyte lysates was also inhibited by Ca2+-selective chelators or by Ca2+ removal by parvalbumin affinity chromatography and the inhibition was reversed by Ca2+. These findings are consistent with the existence of a Ca2+ requirement in the translational phase of protein synthesis in eukaryotic cells.
...
PMID:Identification of a Ca2+ requirement for protein synthesis in eukaryotic cells. 631 27


1 2 3 4 5 6 7 8 9 10 Next >>

---