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)

Type I procollagen secreted by matrix-free chick embryo tendon cells was labeled with L-[3,3'-3H] cystine and purified by DEAE-cellulose chromatography. After bacterial collagenase digestion, the NH2- and COOH-terminal propeptides were partially characterized by ion exchange chromatography and gel filtration. Similar experiments were then conducted after labeling with either D-[6-3H] glucosamine, D-[2-3H] mannose, or D-[U-14C] glucose. On the basis of these studies and subsequent carbohydrate analysis, it was concluded that the COOH-terminal peptide contained greater than 90% of the radioactive carbohydrate which consisted predominantly of glucosamine and mannose with traces of galactosamine and galactose. Only radioactive glucosamine could be detected in the NH2-terminal propeptide. Under conditions which inhibit hydroxylation of lysine and glycosylation of hydroxylysine, unhydroxylated procollagen (protocollagen) could still be labeled with [3H] glucosamine and [3H] mannose. This suggested that glycosylation of the propeptides is at least initiated at the level of the rough endoplasmic reticulum.
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PMID:Localization and partial composition of the oligosaccharide units on the propeptide extensions of type I procollagen. 61 65

Rat hepatocytes, isolated by a collagenase perfusion technique, specifically bind to polyacrylamide gel containing covalently immobilized 6-aminohexyl beta-D-galactopyranosyl groups. Less than 5% of these cells bind to polyacrylamide or to gels with the following covalently linked ligands: 6-aminohexanol, or the 6-aminohexyl D-pyranosides of alpha-mannose, beta-glucose, beta-2-acetamido-2-deoxyglucose, beta-cellobiose, beta-maltose, or beta-melibiose. Cell binding to beta-D-galactoside gels occurs after a lag period at 37 degrees and 65 to 100% (depending on the cell preparation) of the cells adhere. The duration of the lag period is inversely related to the beta-D-galactoside content of the gel but preincubation of the cells at 37 degrees reduces the lag period. Cell-gel binding is a threshold phenomenon. Adhesion of cells to gels does not occur when the glycoside concentration is less than about 900 nmol per cm2 x 0.25 mm thick gel piece. Above this critical concentration, cell-gel binding occurs and becomes maximal when the concentration is increased by only 20%. If these in vitro results apply to cellular interactions in vivo, they suggest that slight changes in the levels of cell surface or extracellular matrix carbohydrates may profoundly influence the behavior of neighboring cells.
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PMID:Specific adhesion of rat hepatocytes to beta-galactosides linked to polyacrylamide gels. 61 72

Complex carbohydrates on the surfaces of eukaryotic cells are thought to participate in a wide variety of cell-cell interactions. A model system has therefore been developed to study these processes. In the present experiments, the ability of chicken hepatocytes to recognize and adhere to sugars covalently linked to polyacrylamide gels was investigated. The gels were snythesized by two methods. Type I gels were prepared from a co-polymer of an active ester of acrylic acid (N-succinimidyl acrylate), acrylamide, and bisacrylamide. The "activated" polyacrylamide gel was then treated with the desired ligand containing an amino group, such as 6-aminohexyl O- or S-glycoside. Type II gels were formed by treating similar ligands with acryloyl chloride, followed by co-polymerization of the resulting N-substituted acrylamide with acrylamide and N,N'-methylenebisacrylamide. These polyacrylamide derivatives offer many advantages for studies with intact cells. They are not toxic to any cell type studied, can be cast in any desired shape, are transparent and stable over a wide range of pH values, and contain no cationic and low to negligible levels of anionic charge (charged groups can be introduced if desired), and the polyacrylamide matrix is stable to common biological agents such as bacteria and enzymes. In addition, type I gels can be synthesized using a broad range of molecules containing amino groups, such as glycopeptides, proteins, etc. The hepatocytes were prepared by collagenase perfusion of intact chicken livers. The rate and extent of adhesion of the cells to the derivatized gels was determined by measuring lactate dehydrogenase in these cells. This enzyme was also used to assay viability and cell "leakiness." At 37 degrees C, 70 to 100% of the cells adhered within 60 min to gels derivatized with N-acetylglucosamine, i.e. gels derivatized with 6-aminohexyl 2-acetamido-2-deoxy-beta-D-glucopyranoside (or the corresponding thioglycoside). By contrast, less than 5% of the cells adhered to polyacrylamide or to gels derivatized with 6-aminohexanol or the 6-aminohexyl glycosides of beta-D-glucose, beta-D-galactose, alpha-D-mannose, beta-D-maltose, beta-D-melibiose, beta-D-cellobiose, and (alpha or beta)-D-lactose. Kinetic studies with the chicken hepatocytes and N-acetylglucosamine gels showed that cell-gel binding was dependent upon Ca2+ and was decreased at low temperatures. Binding was inhibited by N-acetylglucosamine or by glycosides of this sugar, the most effective inhibitor being orosomucoid (alpha1-acid glycoprotein) pretreated with sialidase and beta-galactosidase. The cell surface receptor(s) involved in this interaction is not known, but may be related or identical to the chicken liver binding protein described by Lunney and Ashwell (Lunney, J., and Ashwell, G. (1976) Proc. Natl. Acad. Sci. U. S. A. 73, 341--343). The present results suggest that this model system should prove useful in delineating cell surface interactions with carbohydrates.
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PMID:Adhesion of chicken hepatocytes to polyacrylamide gels derivatized with N-acetylglucosamine. 70 Dec 94

Suspensions of oviduct cells were prepared by subjecting oviduct tissue to sequential incubations with EDTA, alpha-chymotrypsin, and crude collagenase, followed by a final incubation with EDTA. Cells isolated in this way incorporate mannose from exogenous GDP-mannose into mannosyl-lipid, oligosaccharide-lipid, and glycoprotein(s). Based on several criteria, the mannosyl-lipid is identical with mannosyl-phosphoryldolichol. Similarly, the oligosaccharide-lipid appears to be identical with the oligosaccharide-lipid synthesized in vitro (Lucas, J. J., Waechter, C. J., and Lennarz, W. J. (1975) J. Biol. Chem. 250, 1992-2002). In contrast, the glycoproteins are much lower in molecular weight than those labeled in cell-free preparations. Using intact oviduct cell suspensions it was found that: (a) exogenous GDP-mannose, not its breakdown products, serves as the direct mannosyl donor; (b) experiments using mixtures of known proportions of broken and intact cells, as well as studies with metabolic inhibitors, indicate that greater than 50% of the observed incorporation of mannose from GDP-mannose was catalyzed by enzymes associated with intact cells, rather than broken cells or membrane fragments; (c) incorporation of mannose from GDP-mannose into the mannosyl acceptors does not require energy and proceeds without significant uptake of GDP-mannose into trichloroacetic acid-soluble components of the cells; (d) under conditions where labeled guanosine incorporation into nucleic acids is readily detected, no incorporation of the guanosine moiety of [3H]GDP-mannose is observed. These results indicate that the enzymes catalyzing synthesis of lipid-linked intermediates involved in glycoprotein synthesis are not only associated with intracellular membranes, but with the plasma membrane as well.
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PMID:Utilization of exogenous GDP-mannose for the synthesis of mannose-containing lipids and glycoproteins by oviduct cells. 77 Apr 69

The in vitro inhibition of insulin released by alloxan (20 mg/100 ml) in collagenase isolated rat islets is preferentially prevented by alpha D-glucose at a concentration of 1.0 mg/ml, while at a higher anomer concentration (1.5 mg/ml) both alpha and beta D-glucose provide equal protection. The ability of alpha D-glucose compared with beta D-glucose to stimulate insulin release, in vitro, showed a similar dose-related response, as observed in the alloxan protective studies. Although, both alpha and beta D-glucose compete with mutorated D-glucose for transport into islet cells, neither anomer produced a significantly different degree of inhibition in the transport process. The shared alpha stereospecificity for D-glucose in protection against alloxan and in stimulating insulin secretion in these in vitro studies, suggest a common site of interaction which may involve the beta-cell membrane.
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PMID:Effect of anomers of D-glucose on alloxan inhibition of insulin release in isolated perifused pancreatic islets. 78 55

Characterization of glycopeptides obtained on alkaline hydrolysis and on extensive collagenase and pronase digestion of the intestinal basement membrane showed the existence of two distinctly different carbohydrate units. One of these is a disaccharide, composed of glucose and galactose, linked to hydroxylysine. It was shown to be identical to the unit (2-O-D-glucopyranosyl-O-D-galactopyranosylhydroxylyasine) present in vertebrate basement membranes, as determined from stability to alkaline hydrolysis, retention time on amino acid analyzer, chemical composition, graded acid hydrolysis, methylation analysis, and periodate oxidation. Direct quantitation after alkaline hydrolysis showed the presence of 9.71 disaccharide units/1000 amino acid residues, indicating that 89% of the hydroxylysine residues of the intestinal membrane are glycosylated. The other unit, consisting of the remaining monosaccharides of the membrane, was separated from the disaccharide unit by gel filtration and ion exchange chromatography of collagenase/pronase digests. Chemical analyses and molecular weight determination by thin layer gel filtration chromatography of purified glycopeptides indicated that this unit is an oligosaccharide which is composed of fucose, galactose, mannose, galactosamine, and glucosamine in a mole ratio of 1:1:1:1:2, respectively. The amount of this unit was calculated to be 2.6 units/1000 amino acid residues.
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PMID:Intestinal basement membrane of Ascaris suum. Characterization of carbohydrate units. 86 12

1. Isolated lamb liver cells were prepared from 24-h-starved animals by venous perfusion of the excised caudate lobe with buffer containing collagenase. On the basis of Trypan-Blue exclusion, rate of O2 uptake, adenine nucleotide content and retention of constitutive enzymes, these cells were judged to be intact. 2. Isolated caudate-lobe liver cells showed rates of gluconeogenesis from 10 mM-propionate and 10 mM-lactate that compared favourably with rates determined in isolated median-lobe cells and with rates determined with the isolated perfused lamb liver. 3. The gluconeogenic potential of substrates tested depended on the lamb's age. Cells prepared from suckling lambs (up to 20 days of age and essentially non-ruminant) showed highest rates from galactose, serine and alanine; those prepared from post-weaned lambs (older than 30 days of age and ruminant) showed highest rates from propionate, lactate and fructose. 4. Gluconeogenic rates from endogeneous precursors, 10 mM-propionate and 10mM-galactose, were linear for 1 h and were both stimulated by 1 muM-glucagon. Provided the endogenous rate of gluconeogenesis remained unchanged after substrate addition, glucagon caused a net stimulation of gluconeogenesis from each of these substrates. 5. Gluconeogenic capacity and glucagon sensitivity were examined in cells maintained in substrate-free oxygenated buffer at 37 degrees, 22 degrees and * degrees C. Even under the best of the three conditions of storage that were tested (i.e. at 22 degrees C in gelatin-containing buffer) deterioration of the lamb cells proceeded rapidly, and loss of glucagon responsiveness preceeded the loss of ability to convert precursor into glucose. 6. n-Butyric acid, 2-methylpropanoic acid and 3-methylbutanoic acid at concentrations comparable with those found in lamb portal-vein blood each stimulated gluconeogenesis from 10mM-galactose or 10mM-propionate; gluconeogenesis from galactose was stimulated to the greater extent. 7. The regulatory effects of glucagon and sodium butyrate on lamb liver-cell gluconeogenesis and glycogenolysis were compared. Glucagon (1 muM) and 2mM-butyrate accelerated the rate of glucose formation of liver cells of 24h-starved animals from lactate+pyruvate or fructose. Insulin (20nM) decreased both gluconeogenesis and the efficacy of 1 muM-glucagon. For lactate+pyruvate as substrate, the stimulatory effect of butyrate was additive to that of 1muM-glucagon and for both lactate+pyruvate and fructose the stimulatory effect of butyrate was not influenced by 20nM-insulin. In contrast with glucagon, which stimulated the rate of glycogenolysis in cells prepared from fed lambs, butyrate (0.1-20mM) had no effect. 8. It is concluded that glucagon and butyrate stimulate lamb liver-cell gluconeogenesis by different mechanisms.
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PMID:Gluconeogenesis in isolated intact lamb liver cells. Effects of glucagon and butyrate. 94 49

Cells obtained from chick embryo tendons incorporate isotopically labeled glucosamine and mannose into the pro-alpha1 and pro-alpha2 chains of procollagen as judged by sodium dodecyl sulfate-gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The label was further localized to the propeptides of pro-alpha1 and pro-alpha2 by its chromatographic behavior after digestion with bacterial collagenase or alpha-chymotrypsin. Carbohydrate analysis of isolated pro-alpha chains showed the presence of labeled galactosamine in addition to mannose and glucosamine. Resistance to mild alkaline hydrolysis suggested that greater than 90% of the oligosaccharide units are not linked to the propeptide backbone by either serine or threonine.
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PMID:Carbohydrate moieties of procollagen: incorporation of isotopically labeled mannose and glucosamine into propeptides of procollagen secreted by matrix-free chick embryo tendon cells. 106 Nov 25

The in vitro effect of alloxan exposure on the permeability of collagenase isolated rat pancreatic islets to sucrose, D-mannitol, and L-glucose has been investigated. Determination of changes in cell volume with a non-wash double label isotope procedure indicates that alloxan treatment exerts no measurable effect on permeability to sucrose, D-mannitol, or L-glucose as compared to nonalloxan-treated islets. In addition, neither prior exposure nor the concomitant presence of alloxan alters the rate of D-glucose or 3-0-methyl-D-glucose transport into rat pancreatic islets. It is concluded that the in vitro effect of alloxan on abolishing glucose-induced insulin release in isolated rat pancreatic islets does not appear to be the result of permeability changes to small organic molecules or alteration in the transport of D-glucose into the beta-cell.
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PMID:Effect of alloxan on permeability and hexose transport in rat pancreatic islets. 109 63

A forty-kilodalton (40-kDa) protein was extracted from alveolar bone of young adult rabbit with 0.5 M EDTA after extraction with 4 M GuHCl, and purified by gel-filtration, anion-exchange and hydroxyapatite columns using a high-pressure liquid chromatography system under denaturing conditions. The purified 40-kDa protein was not susceptible to bacterial collagenase and thrombin, but was cleaved by cyanogen bromide. The protein was stained blue with Stains-all. Among various lectins, concanavalin A and lentil lectin agglutinin bound to this protein, but peanut agglutinin, Ricinus communis agglutinin, phytohemagglutinin-E and wheatgerm lectin agglutinin did not. Lectin binding assays showed that the protein is a glycoprotein containing large amounts of mannose and/or glucose residues, but is not a fragment of proteoglycan. The amino acid composition of the protein shows a characteristically high content of acidic amino acids. Therefore, the mineral-binding 40-kDa glycoprotein is considered to be osteonectin/secreted protein acidic and rich in cysteine (SPARC), in terms of similarities to bovine and porcine osteonectins with regard to molecular weight and contents of glycoses and amino acids.
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PMID:Characterization of mineral-binding 40-kDa glycoprotein extracted from young adult rabbit alveolar bone. 132 44


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