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)

Rates of synthesis and secretory release and the maximal requisite intracellular transit time (Tsec) for lactose were measured in vitro for three preparations of lactating guinea pig mammary tissue: tissue slices, mammary epithelial cell (MEC) acini, and mono-dispersed MEC. The Tsec values for tissue slice and acini preparations were similar, lactose required approximately 16 min to pass from its site of synthesis (Golgi) to the extracellular medium. Dispersal of mammary tissue into single cells by collagenase disruption of all cell-cell junctional complexes increased the Tsec value to approximately 25 min but did not alter kinetics of lactose synthesis and secretory release. These data suggest a possible involvement of cell-cell junctional contacts in intracellular transport of lactose.
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PMID:A putative role for cell-cell epithelial contacts in lactose secretion. 54 94

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

IgE-binding protein (epsilon BP) was originally identified by virtue of its affinity for IgE. It is now known to be a beta-galactoside-binding lectin with the characteristic of an S-type carbohydrate recognition domain. The protein is composed of two domains: the amino-terminal domain consisting of tandem repeats and the carboxyl-terminal domain containing sequences shared by other S-type carbohydrate recognition domains. The amino-terminal domain also contains a number of potential recognition sites for collagenase cleavage. In this study, human epsilon BP was first expressed in Escherichia coli, and the carboxyl-terminal domain (epsilon BP-C) was then generated by collagenase digestion of epsilon BP. By equilibrium dialysis, the association constants of epsilon BP and epsilon BP-C for lactose were found to be similar (6.0 +/- 0.70) x 10(4) M-1 and (4.7 +/- 0.27) x 10(4) M-1, respectively. Both polypeptides contain only one lactose-binding site/molecule. By an assay involving binding of 125I-labeled epsilon BP or epsilon BP-C to solid phase IgE, and inhibition of this binding by saccharides, it was determined that epsilon BP-C retains the saccharide specificity of epsilon BP. Importantly, although unlabeled epsilon BP-C inhibited the binding of the radiolabeled epsilon BP to IgE, unlabeled epsilon BP caused increased binding to IgE, suggesting self-association among epsilon BP molecules. Oligomeric structures resulting from self-association of epsilon BP were confirmed by chemical cross-linking studies. Furthermore, epsilon BP possesses hemagglutination activity on rabbit erythrocytes, whereas epsilon BP-C lacks such activity. Based on these results, we propose a structural model for multivalency of epsilon BP: dimerization or oligomerization of epsilon BP occurs through intermolecular interaction involving the amino-terminal domain.
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PMID:Biochemical and biophysical characterization of human recombinant IgE-binding protein, an S-type animal lectin. 162 16

The adhesion of Erysipelothrix rhusiopathiae (E. rhusiopathiae) to the cultured confluent monolayer of rat aortic endothelial cells (EC) and the role of neuraminidase in the interaction between EC and E. rhusiopathiae were examined. One EC line was obtained by collagenase treatment of rat aorta. The EC showed a typical cobblestone appearance and possessed the factor VIII related antigen. When cultured more than two weeks after reaching confluence, the EC formed a vascular plexus-like appearance. E. rhusiopathiae began to adhere to EC within 2 minutes after the beginning of culture and adhered at a constant rate for 20 minutes. The adhesion of bacteria to EC was closely related to the release of sialic acid from the EC. Significantly more bacteria adhered to neuraminidase treated EC, and bacterial adhesion was inhibited dose-dependently by N-acetylneuraminic-lactose, which is the substrate of bacterial neuraminidase. It is concluded that bacterial neuraminidase plays an essential role in initiating the interaction between EC and E. rhusiopathiae, which would contribute to the genesis of arteritis.
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PMID:Adhesion of Erysipelothrix rhusiopathiae to cultured rat aortic endothelial cells. Role of bacterial neuraminidase in the induction of arteritis. 360 4

Vibrio vulnificus (lactose-positive vibrio) produced collagenase when grown in 2% synthetic sea salts supplemented with hydrolyzed casein. The addition of collagen or peptone to the medium increased the level of collagenase production. Collagenase activity was inhibited by EDTA but not by fetal calf serum.
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PMID:Collagenolytic activity of Vibrio vulnificus: potential contribution to its invasiveness. 627 15

Mammary epithelial cells were prepared by collagenase digestion of tissue from mid-pregnant rabbits and cultured for up to 6 days on either collagen gels or an extracellular matrix prepared from the same tissue. The behaviour of the cells in serum-supplemented medium containing combinations of insulin, prolactin, hydrocortisone, estradiol and progesterone were monitored by measuring rates of casein synthesis, lactose synthesis, DNA synthesis and protein degradation. After 6 days, epithelial cells on floating collagen gels showed substantial increases in casein synthesis and DNA synthesis over freshly-prepared cells, following a decline during the first 3 days when the collagen gels are contracting. The optimum hormone combination for casein synthesis was insulin + prolactin + hydrocortisone, whereas for optimum DNA synthesis the additional presence of estradiol and progesterone was required. Cells on extracellular matrix showed increased rates of both casein synthesis and DNA synthesis by day 6 in the presence of insulin + prolactin + hydrocortisone, with additional estradiol + progesterone having an inhibitory effect. Whereas on day 2 rates of intracellular protein degradation were generally lower in cells on extracellular matrix, by day 6 rates of protein degradation were lowest in cells cultured on collagen gels with insulin + prolactin + hydrocortisone. In all cases, rates of lactose synthesis fell to low levels as the culture proceeded. Pulse-chase labelling of freshly-prepared cells with [32P]orthophosphate in medium containing serum and insulin + prolactin + hydrocortisone demonstrated that newly-synthesized casein was degraded during its passage through the epithelial cell. The influences of the collagen gels and extracellular matrix and of the hormone combinations on epithelial cell differentiation and secretory activity are discussed.
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PMID:Comparison of collagen gels and mammary extracellular matrix as substrata for study of terminal differentiation in rabbit mammary epithelial cells. 670 39

A lactose-binding lectin from rat lung (RL-29) and a related lectin from Madin-Darby canine kidney (MDCK) cells have been analyzed with the primary goal of identifying post-translational modifications. The sequences show that RL-29 and the dog lectin are homologues of a lectin designated here as L-29 and elsewhere as CBP-35, epsilon BP, Mac-2, or L-34. RL-29 has a 140-amino-acid COOH-terminal carbohydrate-binding domain, a 20-amino-acid NH2-terminal domain, and an intervening domain consisting of 11 repeating elements rich in Pro, Gly, and Tyr (R-domain). The dog homologue has 14 repeating elements in its R-domain explaining its larger size. The sensitivity of the R-domain to bacterial collagenase allowed us to isolate the NH2-terminal domain and show that the NH2 terminus was blocked by acetylation and, in the accompanying paper (Huflejt, M. E., Turck, C. W., Lindstedt, R., Barondes, S. H., and Leffler, H. (1993) J. Biol. Chem. 268, 26712-26718), that the NH2-terminal domain is phosphorylated. In addition, we unexpectedly found an endogenous component, resembling 92-kDa type IV collagenase, that co-purified with L-29 and slowly digested the R-domain. Hence, L-29 is a substrate for bacterial and tissue collagenases even though the R-domain is non-collagenous. Moreover, the co-purification suggests a non-enzymatic interaction between 92-kDa collagenase and L-29.
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PMID:Primary structure of the soluble lactose binding lectin L-29 from rat and dog and interaction of its non-collagenous proline-, glycine-, tyrosine-rich sequence with bacterial and tissue collagenase. 825 5

Mouse mannan-binding protein (MBP) was identified in serum by its Ca(2+)-dependent binding to mannan. On gel permeation chromatography, the protein eluted corresponding to a molecular weight of approximately 750 kDa. Analysed on SDS-PAGE under reducing conditions, the polypeptide showed an apparent molecular weight of 28 kDa, while several high molecular weight bands were seen under non-reducing conditions. The presence of collagen-like domains within the molecule was indicated by a high glycine content (14.9%) and substantiated by sensitivity to collagenase. Rabbit anti-mouse MBP antisera were raised. The concentration of MBP in serum from normal mice was measured by rocket immunoelectrophoresis and found to be from below 1 microgram/ml to 100 micrograms/ml (average 50 micrograms/ml, n = 60). The binding of mouse MBP to mannan could be inhibited by mono- and disaccharides in the following order of potency: L-fucose > D-mannose > N-acetyl-D-glucosamine > maltose > D-mannoheptulose > D-glucose > N-acetyl-D-mannosamine >> lactose > D-galactose >> N-acetyl-D-galactosamine. Mouse MBP was shown to activate the classical complement cascade after binding to mannan. The sequence of 14 NH2-terminal amino acid residues of the molecule showed 93% identity to rat MBP-A and complete identity to the translated cDNA sequences for mouse MBP-A and mouse Ra-reactive factor component P28b (RaRF P28b) published previously. The amino acid composition of mouse MBP showed a high degree of homology to MBPs from other species and mouse RaRF P28b.
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PMID:Purification and characterization of mannan-binding protein from mouse serum. 829 64

A galactoside-binding lectin (hL-31) containing a collagen-like sequence was identified in human tumor cells. It was found to be the homologue of the IgE-binding protein, the macrophage cell-surface Mac-2 antigen, and the murine CBP35, RL-29, and mL-34 lectins. Here we report on the expression in Escherichia coli and functional analysis of recombinant hL-31 (rhL-31). The rhL-31 was purified in one step through an asialofetuin affinity column. The rhL-31 was reactive to anti-lectin antibodies and retained its lactose-dependent hemagglutination of trypsin-treated glutaraldehyde-fixed rabbit erythrocytes. The rhL-31 elutes from an affinity column as a 31-kDa monomer and undergoes homodimerization at relatively high protein concentrations, comparable to those used to mediate hemagglutination. Electron microscopy showed that the rhL-31 appears as a Y-shaped structure. Lactoperoxidase-catalyzed iodination of murine tumor cell-surface proteins followed by collagenase treatment revealed that the lectin is probably a peripheral membrane protein whereby both the amino and the carboxy termini are exposed on the outer cell membrane. These results point to the membrane disposition and orientation of the lectin and suggest a mechanism for a structure-function relationship of lectin activity.
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PMID:Structure-function relationship of a recombinant human galactoside-binding protein. 847 70

A previously undescribed bovine serum lectin (designated CL-43) was identified by its Ca(2+)-dependent binding to mannan and by its molecular mass of 43 kDa under reducing conditions on SDS-PAGE. The lectin was isolated by polyethylene glycol precipitation, affinity chromatography on mannan-Sepharose (followed by elution with EDTA), and absorption on Sepharose-4B-coupled rabbit anti-bovine Ig (to remove anti-mannan antibodies). Fractions containing the lectin were reapplied to mannan-Sepharose. Bound conglutinin was eluted with GlcNAc, and then the 43-kDa lectin, together with mannan-binding protein (MBP), was eluted with mannose. The 43-kDa lectin was separated from MBP by ion exchange chromatography on Mono-Q. On SDS-PAGE under nonreducing conditions the lectin showed a molecular mass of 120 kDa. On gel chromatography under nondissociating conditions the protein was eluted at a volume corresponding to a molecular mass of approximately 750 kDa. Amino acid analysis showed the presence of hydroxyproline and hydroxylysine and a high content of glycine (24.3%) indicating the presence of a collagen-like structure. This was supported by the susceptibility of the protein to collagenase digestion. The designation CL-43 was chosen since this molecule appears to belong to the collectins, i.e. proteins with collagen structure and lectin activity. The N-terminal sequence (27 amino acids) showed 56% identity with bovine SP-D and 44% identity to bovine conglutinin. An inhibition assay with biotinylated CL-43, using solid-phase mannan as ligand, revealed the following carbohydrate inhibition pattern: mannose and ManNAc > fucose > GlcNAc > glucose and maltose > galactose > lactose >> GalNAc. We conclude that CL-43 is a circulating lectin, with structural similarities to bovine conglutinin and SP-D, and a ligand binding profile resembling that of MBP.
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PMID:Purification and characterization of a bovine serum lectin (CL-43) with structural homology to conglutinin and SP-D and carbohydrate specificity similar to mannan-binding protein. 848 82


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