Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biochemical and histochemical parameters of intestinal mucins were examined in control and reserpine-treated rats. An assay for intestinal mucin sulfotransferase was developed and the activity shown to increase 3.4 times over control levels in rats given intraperitonal reserpine (0.5 mg/kg body wt) daily for 7 days. Histochemical staining of intestinal sections revealed an increase in sulfomucins in goblet cells of reserpine-treated rats. The effects were prominent as early as 1 day following injection, particularly in the distal third of the small intestine, and during the next 6 days these changes spread progressively to the middle and proximal thirds. After 3 days of treatment mucins were purified from each intestinal segment and compared to control mucins with respect to composition and [35S]NaSO4 incorporation. Although individual amino acid and carbohydrate molar ratios were unchanged, the total carbohydrate and sulfate content of mucins in treated animals was elevated (two to three times above control) in the middle and distal thirds of the intestine. In vivo [35S]SO4 incorporation into these mucins was also proportionaltely elevated, and was targetted to O-linked oligosaccharide side chains. These findings are consistent with an action of reserpine causing an increased production of mucin which is enriched in glycoprotein components bearing sulfated oligosaccharide chains. The relevance of these findings to the production of hypersulfated and hyperglycosylated mucins in cystic fibrosis is discussed.
Exp Mol Pathol 1991 Apr
PMID:Effect of reserpine on the histochemical and biochemical properties of rat intestinal mucin. 202 34

The oligosaccharide chains in human and swine trachea and Cowper's gland mucin glycoproteins were completely removed in order to examine the subunit structure and properties of the polypeptide chains of these glycoproteins. The carbohydrate, which constitutes more than 70% of these glycoproteins, was removed by two treatments with trifluoromethanesulfonic acid for 3 h at 3 degrees and periodate oxidation by a modified Smith degradation. All of the sialic acid, fucose, galactose, N-acetylglucosamine and N-acetylgalactosamine present in these glycoproteins was removed by these procedures. The deglycosylated polypeptide chains were purified and characterized. The size of the monomeric forms of all three polypeptide chains were very similar. Data obtained by gel filtration, release of amino acids during hydrolysis with carboxypeptidase B and gel electrophoresis in the presence of 0.1% dodecyl sulfate showed that a major fraction from each of the three mucin glycoproteins had a molecular size of about 67 kDa. All of the deglycosylated chains had a tendency to aggregate. Digestion with carboxypeptidases showed that human and swine trachea mucin glycoproteins had identical carboxyl terminal sequences, -Val-Ala-Phe-Tyr-Leu-Lys-Arg-COOH. Cowper's gland mucin glycoprotein had a similar carboxyl terminal sequence, -Val-Ala-Tyr-Leu-Phe-Arg-Arg-COOH. The yield of amino acids after long periods of hydrolysis with carboxypeptidases showed that at least 85% of the polypeptide chains in each of the deglycosylated preparations have these sequences. These results suggested that the polypeptide chains in these deglycosylated mucin glycoprotein preparations were relatively homogeneous. The deglycosylated polypeptide chains as well as the intact mucin glycoproteins had blocked amino terminii. The purified polypeptide chains were digested with trypsin-TCPK, and S. aureus V8 protease and the resulting peptides were isolated by gel electrophoresis in the presence of 0.1% dodecyl sulfate and by HPLC. Two partial amino acid sequences from swine trachea mucin glycoprotein, two partial sequences from human trachea mucin glycoprotein and three partial sequences from Cowper's gland mucin glycoprotein were determined. The partial amino acid sequences of the peptides isolated from swine trachea mucin glycoprotein showed more than 70% sequence homology to a repeating sequence present in porcine submaxillary mucin glycoprotein. Five to eight immunoprecipitable bands with sizes ranging from about 40 kDa to 46 kDa were seen when the polypeptide chains were digested with S. aureus V8 protease. All of the bands had blocked amino terminii and differed by a constant molecular weight of about 1.5 kDa.(ABSTRACT TRUNCATED AT 400 WORDS)
Mol Cell Biochem 1991 Mar 27
PMID:Subunit structure of deglycosylated human and swine trachea and Cowper's gland mucin glycoproteins. 205 1

Crystals have been obtained of a chimaeric Fab' fragment that binds to a tumour-associated mucin-like glycoprotein TAG72. The Fab' fragment comprises the variable heavy and light-chain domains of a murine monoclonal antibody, B72.3, coupled to human gamma 4 and kappa constant regions. The crystals are orthorhombic and belong to the space group P2(1)2(1)2(1), with unit cell dimensions a = 67.9 A, b = 94.2 A and c = 208.8 A. Diffraction to 2.6 A resolution was observed using synchrotron radiation. Despite the acute radiation sensitivity of the crystals a full native data set has been collected using the Weissenberg camera at the Photon Factory synchrotron. These data will be used for molecular replacement calculations in an attempt to elucidate the structure of this chimaeric Fab' fragment.
J Mol Biol 1991 Jun 20
PMID:Crystallization and preliminary X-ray diffraction study of a chimaeric Fab' fragment of antibody binding tumour cells. 205 29

One of the mouse sperm surface binding sites for zona pellucida ligands exhibits galactosyltransferase (GT) enzyme activity. The present study was undertaken to ascertain whether the GT site behaves as a noncatalytic binding site in its physiological capacity, with no glycosylation of zona ligands, or whether glycosylation of zona ligands is an integral part of sperm-zona binding. The effects of Mn2+, the obligatory cation for GT catalysis, on enzyme activity and sperm-zona binding were examined. With uridine-5'-diphosphogalactose (UDPgal) as galactose donor, and N-acetylglucosamine (GlcNAc) as galactose acceptor, increasing concentrations of Mn2+ in the range of 0.1-10 mM increased GT enzyme activity, with half-maximal activation at 0.65 mM Mn2+ (Vmax = 20 pmol/hr/10(6) cells). In the presence of 0-2 mM Mn2+, sperm-zona binding was inhibited in a concentration-dependent manner; 50% inhibition occurred at 1.25 mM Mn2+. At this concentration, GT enzyme activity was at 65% Vmax. To determine the specificity of the GT site for glycoprotein terminal carbohydrate residues, spermatozoa were incubated with, asialo-ovine submaxillary mucin (N-acetylgalactosamine residues), asialo-, -alpha 1-acid glycoprotein (beta 1-4 galactose residues) ovalbumin (Ov; GlcNAc residues), and asialo-agalacto-/alpha 1-acid glycoprotein (AsAgAGP; GlcN-Ac residues). Only Ov and AsAgAGP acted as acceptors for galactose in the enzyme assay and inhibitors in the sperm-zona binding assay. The kinetics of the interaction of AsAgAGP with the GT site were determined: the Km was 3.6 mg/ml, with Vmax of 33 pmol/hr/10(6) cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Reprod Dev 1990 Apr
PMID:Further characterization of the mouse sperm surface zona-binding site with galactosyltransferase activity. 210 19

Lymph node (LN) T cells from autoimmune MRL/MpJ-lpr/lpr (lpr) mice and control MRL/MpJ-(+)/+ (+/+) mice were compared as to glycosyl transferase activities involved in the biosynthesis of polylactosaminoglycans. The N-acetylglucosaminyl transferase (GlcNAc transferase) activity responsible for the extension of polylactosaminoglycans was assayed. The reaction products with this GlcNAc transferase were characterized by sequential glycosidase treatment and methylation analysis, and the enzyme was found to be classifiable as an UDP-GlcNAc:N-acetyllactosamine beta 1-3 GlcNAc transferase (polylactosamine extension enzyme). The activity of this GlcNAc transferase in T cells from enlarged LN of lpr mice was 3-6 times higher than that in T cells from +/+ mice. On the other hand, activated T cells from +/+ mice only showed about a 2-fold increase in the activity of the transferase, compared with that in resting T cells. B cells from +/+ mice also showed a significantly higher activity of the transferase than +/+ T cells, the enzyme activity being comparable to or slightly lower than that in lpr T cells. Furthermore, when the reaction mixture contained both UDP-GlcNAc and UDP-Gal as donors, extension of the Gal-GlcNAc residue was observed. These results indicated the biosynthetic basis for the abundance of polylactosaminoglycans in lpr T cells and normal B cells. We also found that lpr T cells exhibited significant UDP-GlcNAc:asialo-bovine submaxillary mucin GlcNAc transferase activity. Only weak activity of this enzyme was detected in +/+ resting and activated T cells, and B cells. This enzyme activity suggested the potential for polylactosaminoglycan formation on the mucin-type sugar chains on the surface of lpr T cells.
Mol Immunol 1990 Apr
PMID:Elevation of the activities of glycosyl transferases involved in polylactosaminoglycan biosynthesis in autoimmune MRL lpr/lpr mouse T cells. 214 66

The effects of culture conditions on growth and differentiation of human tracheobronchial epithelial (HTBE) cells have been defined. Epithelial cells were dissociated from tissues by protease treatment and were plated on tissue culture dishes in F12 medium supplemented with insulin, transferrin, epidermal growth factor, hydrocortisone, cholera toxin, bovine hypothalamus extract, and retinol. HTBE cells did not express any mucociliary function (ciliogenesis or mucin secretion) on tissue culture plastic, but they could be passaged 3 to 5 times with a total of 10 to 25 population doublings. Cells from early passages re-express both these functions when transplanted to tracheal grafts. When tissue culture plates were coated with collagen film or collagen gel substrata, cell attachment and proliferation were stimulated. However, the expression of mucous cell function in culture occurred only when cells were plated on collagen gel substrata and vitamin A (retinol) was present in the medium. Mucous cell differentiation under optimal conditions was defined by ultrastructural studies, by immunologic studies with mucin-specific monoclonal antibodies, and by carbohydrate and amino acid compositional analyses of mucin-like glycoproteins purified from culture medium. These results demonstrate for the first time that HTBE cells can express mucin synthesis and secretion under appropriate culture conditions.
Am J Respir Cell Mol Biol 1990 Nov
PMID:Expression of mucin synthesis and secretion in human tracheobronchial epithelial cells grown in culture. 222 1

The objective of this research was to study efficiency of embryo development following transfer of blastomeres into the perivitelline space of oocytes. Single blastomeres from 8-, 16-, and 32-cell embryos were obtained following mucin coat and zona pellucida removal by combined treatments with pronase and acidic phosphate-buffered saline (PBS, pH = 2.5). Blastomeres were separated by pipetting with a fire-polished micropipette following incubation in Ca+(+)-free PBS for 15 min at 39 degrees C. This procedure resulted in over 97% blastomere separation. For ease of blastomere insertion, oocytes were placed in droplets of 0.5 M sucrose in PBS (SPBS) during micromanipulation. To functionally enucleate oocytes some were stained with Hoechst 33342 DNA stain and irradiated. A single 8- or 16-cell blastomere was aspirated into an injection pipette (35 microns or 25 microns at the tip, respectively) and inserted into the perivitelline space of an irradiated or non-irradiated oocyte, but not fused with the oocyte. This micromanipulation procedure did not affect development of individual blastomeres into blastocysts or trophectoderm vesicles when compared with cultured control single blastomeres (P greater than .05). When the inserted blastomere was induced to fuse with an intact non-irradiated oocyte under an electric field, 56-57% were fused and 39-45% of the fused and activated oocytes developed to morulae or blastocysts. When an inserted blastomere (from 8-32-cell embryos) was induced to fuse with a functionally enucleated oocyte treated by Hoechst 33342 staining, followed by washing and UV-light irradiation, 63-66% of them were fused, but only 15-22% developed to the morula or blastocyst stage. This research demonstrated that the use of hypertonic medium treated oocytes greatly improved the ease and success rate of blastomere subzona insertion, but the value of functionally enucleated oocytes as recipient cells for nuclear transfer requires further investigation.
Mol Reprod Dev 1990 Oct
PMID:Potential of hypertonic medium treatment for embryo micromanipulation: II. Assessment of nuclear transplantation methodology, isolation, subzona insertion, and electrofusion of blastomeres to intact or functionally enucleated oocytes in rabbits. 224 75

An air-liquid interface (biphasic) primary culture system in which guinea pig tracheal epithelial cells maintain morphologic characteristics of differentiated epithelium has been developed in this laboratory. In this report, we compared quantitatively cell populations of 8-day cultures to those of epithelial mucosa in intact trachea. In addition, high molecular weight glycoconjugates released by the cultured cells were isolated and characterized. Quantitative morphometric analysis revealed similar volume densities of ciliated, secretory, basal, and "other" cells in cultures and in intact tracheal surface epithelium, although the cultures tended to have smaller cells and contained fewer basal cells. High molecular weight glycoconjugates released apically by cell cultures and excluded from Sepharose CL-4B columns contained approximately 5% hyaluronic acid but undetectable amounts of other proteoglycans, such as chondroitin sulfate, heparan sulfate, and dermatan sulfate. The hyaluronidase-resistant glycoconjugates exhibited a peak buoyant density at 1.49 g/ml on cesium chloride density gradient centrifugation and were shown to contain mucin-type carbohydrate to peptide linkages (i.e., GalNAc to ser/thr) and an amino acid composition typical of respiratory mucins. The results indicate that this organotypic cell culture system mimics quite closely morphology of mucosal epithelium in intact airways and that the cells release high molecular weight glycoconjugates with biochemical properties of mucin-type glycoproteins. Thus, this in vitro system appears well-suited for studies of mucin secretion and other functions of respiratory epithelial cells.
Am J Respir Cell Mol Biol 1990 Feb
PMID:Characterization of guinea pig tracheal epithelial cells maintained in biphasic organotypic culture: cellular composition and biochemical analysis of released glycoconjugates. 230 71

Hybridoma generation, using specifically, maximally desialylated human blood group O erythrocytes (T RBC) as immunogen, and biochemical studies suggested the presence of immunogenic Tn epitopes. GalNAc alpha-O, on T RBC. We therefore investigated by immunochemical means whether or not Tn-specific epitopes immunoreactive with anti-Tn antibodies present in ordinary human sera occur on T RBC and on Thomsen-Friedenreich (T) antigen prepared from them. We did detect the Tn epitope with such antibodies, in addition to the T epitope, on isolated T antigen. T RBC absorbed specifically, under standard conditions, 25-60% of the heterogeneous anti-Tn antibody populations in ordinary human sera of appropriately adjusted titer score. The anti-Tn eluted from T RBC had scores ranging from 6.5 to 35% of those of the unabsorbed parent sera. The varying fine specificities of eluted anti-Tn were demonstrated by inhibition of Tn RBC agglutination with putative haptens and antigens. Tn-specific haptens and antigens were the most powerful inhibitors. Depending on the serum used to prepare the anti-Tn eluates, the antibodies could be divided into those that were inhibited well exclusively by GalNAc alpha-O derivatives and those that were also inhibited by Gal, notably by Gal alpha-O derivatives and more strongly by GalNAc and Me-alpha-GalNAc. In the two reciprocal hemagglutination inhibition systems used, Tn-specific haptens were considerably more active than the T-hapten Gal beta 1----3GalNAc alpha-O, and desialylated ovine submaxillary mucin (AS-OSM) had higher activity than T antigen. Inhibition of Tn RBC agglutination by haptens was uniformly more efficient than that of T RBC; this is, at least in part, due to the much higher negative charge of Tn as opposed to T RBC. In microprecipitin tests, Helix pomatia lectin was nearly as powerful a precipitin of T antigen as of AS-OSM. The importance of the terminal GalNAc alpha of T antigen for its precipitation with the Helix lectin was demonstrated by the very high and virtually exclusive inhibitory activity of Me-alpha-GalNAc and GalNAc. Our findings may contribute to comprehension of the significance of uncovered Tn in most carcinomas, and the role of anti-Tn as a "natural" anti-carcinoma antibody. They may also help illuminate the rare heterozygous, autosomal, apparently premalignant spot mutation that leads to Tn RBC in vivo.
Mol Immunol 1985 Nov
PMID:Tn epitopes, immunoreactive with ordinary anti-Tn antibodies, on normal, desialylated human erythrocytes and on Thomsen-Friedenreich antigen isolated therefrom. 241 12

A sialic acid binding lectin, AchatininH, was purified in single step from the hemolymph of the land snail, Achatina fulica, by the affinity chromatography on sheep submaxillary mucin coupled to Sepharose 4B. The yield of the lectin was found to be 3 mg from 100 ml of hemolymph. The homogeneity of the lectin was established by alkaline gel electrophoresis, immunodiffusion, immunoelectrophoresis and analytical isoelectrophoresis. The molecular weight of the native protein was 242,000, having identical subunits of Mr 15,000. The lectin agglutinated rabbit erythrocytes in the presence of Ca2+. The inhibition study clearly suggests that the binding site of the lectin recognizes sialic acid as the immunodominant sugar. This was further confirmed by the observation that there was a marked decrease of agglutinating activity of the lectin with neuraminidase treated rabbit erythrocytes and asialofetuin was unable to inhibit the activity of AchatininH. Among the inhibitors used the glycoconjugate containing alpha 2----6 linkages of N-acetylneuraminic acid with subterminal galactopyranose or 2-acetamido-2-deoxy-galactopyranose residue was found to be better inhibitor than that containing alpha 2----3 linkages of N-acetyl neuraminic acid. Besides that sialoglycoprotein containing both N and O type of glycosidic linkages plays an important role in binding with the lectin. Fetuin was found to be the best inhibitor.
Mol Cell Biochem 1986 Aug
PMID:A single step purification of a sialic acid binding lectin (AchatininH) from Achatina fulica snail. 243 Jan 70


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