Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “GLYCOLIPIDS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
PubMed1979

Radioimmunoassay of glycosphingolipids: application for the detection of forssman glycolipid in tissue extracts and cell membranes.

Development of a radioimmunoassay for detecting glycosphingolipids has been difficult, primarily because of transfer of radiolabeled glycolipid antigen to the unlabeled antigen pool. This difficulty has been overcome by the use of a radiolabeled glycolipid-polymer. Thus, an assay system has been developed for measuring picomolar quantities of Forssman hapten glycolipid. This assay is based on competition for rabbit anti-Forssman antibodies between Forssman glycolipid and a radiolabeled Forssman polyacrylic hydrazide polymer. Antigen-antibody complexes are removed quickly and efficiently by binding to formalin-fixed Staphylococcus aureus and subsequent centrifugation. One nanogram of Forssman glycolipid can be readily detected both in plasma membrane preparations and in purified glycolipid fractions. The isoantigenic expression of Forssman glycolipid in human gastrointestinal tissues has been reported previously (Hakomori et al., 1977). Using the radioimmunoassay, the Forssman status of several additional cases has been determined quantitatively.

Animals↗
PubMed2005

Glycolipid presentation to natural killer T cells differs in an organ-dependent fashion.

It has been shown that dendritic cells (DCs) are able to present glycolipids to natural killer (NK) T cells in vivo. However, the essential role of DCs, as well as the role of other cells in glycolipid presentation, is unknown. Here, we show that DCs are the crucial antigen-presenting cells (APCs) for splenic NK T cells, whereas Kupffer cells are the key APCs for hepatic NK T cells. Both cell types stimulate cytokine production by NK T cells within 2 h of glycolipid administration, but only DCs are involved in the systemic, downstream responses to glycolipid administration. More specifically, CD8alpha+ DCs produce IL-12 in response to glycolipid presentation, which stimulates secondary IFN-gamma production by NK cells in different organs. Different APCs participate in glycolipid presentation to NK T cells in vivo but differ in their involvement in the overall glycolipid response.

Animals↗
PubMed1994

Pili and lipopolysaccharide of Pseudomonas aeruginosa bind to the glycolipid asialo GM1.

This study investigated which adhesins of Pseudomonas aeruginosa interact with the glycolipid asialo GM1, using solid-phase binding and thin-layer chromatography assays. Radioiodinated pili and flagella contaminated with lipopolysaccharide (LPS) bound to the glycolipid. When LPS was reduced to acceptable levels in pilus and flagellum samples, only pili specifically bound to the glycolipid. Commercial, radiolabeled LPS as well as whole bacteria of strain ATCC 19660 also bound to asialo GM1. Binding was specific, competitive, and saturable. Organ cultures of whole mouse eyes and scanning electron microscopy techniques were used also, and strain ATCC 19660 was inhibited from corneal binding by exogenous pili or commercial LPS and inhibition was concentration dependent for both. Binding of radiolabeled strain ATCC 19660 bacteria to neutral lipids extracted from bovine corneal epithelial tissue showed that the bacteria bound to a glycolipid which migrated at a position similar to that of an asialo GM1 standard and that the glycolipid stained positively with an antibody specific for asialo GM1. The data provide evidence that pili (reduced LPS) and LPS of P. aeruginosa bind to asialo GM1 glycolipid and that the glycolipid is not restricted to the mouse cornea.

Adhesins, Bacterial↗
PubMed1985

Structures of glycosphingolipids isolated from human granulocytes. The presence of a series of linear poly-N-acetyllactosaminylceramide and its significance in glycolipids of whole blood cells.

Structures of glycolipids isolated from human granulocytes were elucidated by fast atom bombardment-mass spectrometry, methylation analysis, and exo- and endoglycosidase treatment. All neutral glycolipids, with saccharide residues ranging from 2 to 10, were found to have linear N-acetyllactosaminyl backbones. The majority of neutral glycolipids contain one or two fucosyl residues attached to N-acetylglucosamine residues through the Fuc alpha 1----3 linkage and were reactive with the monoclonal antibody specific to Gal beta 1----4(Fuc alpha 1----3)GlcNAc, the Lex structure. Their general structure can be expressed as follows: (formula; see text) where n = 0-3. Glycolipids containing sialic acid (gangliosides) were also found to have linear N-acetyllactosaminyl backbones with sialic acid joined to this backbone by either alpha 2----3 or alpha 2----6 linkage. The gangliosides have the following general structure: (formula; see text) where n = 0-3. The ceramide was composed of sphingosine with d18:1 as the long-chain base and C16:0 (as a major component) or C24:1 (as a minor component) fatty acid. Analysis of glycolipids isolated from granulocytes, erythrocytes, and whole blood cells revealed that, among the glycolipids prepared from the whole blood cells, dihexaosylceramide, lactoneotetraosylceramide, and the above described linear lactoneo series neutral glycolipids are present in granulocytes but barely present in erythrocytes.

Antibodies, Monoclonal↗
PubMed1998

Degradation of blood group A glycolipid A-6-2 by normal and mutant human skin fibroblasts.

The degradation of blood group glycolipid A-6-2 (GalNAc(alpha1-->3)[Fuc alpha1-->2]Gal(beta1-->4)GlcNAc(beta1-->3)Gal(beta1-->4)Glc(beta1-->1')C er, IV2-alpha-fucosyl-IV3-alpha-N-acetylgalactosaminylneolact otetraosylceramide), tritium-labeled in its ceramide moiety, was studied in situ, in skin fibroblast cultures from normal controls, from patients with defects of lysosomal alpha-N-acetylgalactosaminidase, and from patients with other lysosomal storage diseases. Uptake of the glycolipid with apolipoprotein E-coated liposomes was linear with time and with the amount of glycolipid added. In normal cells, the expected array of less polar products and some lipids resulting from re-using the liberated sphingosine, mainly sphingomyelin and phosphatidylcholine, were formed. In alpha-N-acetylgalactosaminidase-deficient cells, the glycolipid was virtually not degraded; product formation was less than 2% of the normal control rate, suggesting that blood group A-active glycolipids contribute as storage compounds to the pathogenesis of this disease. The expected accumulation of degradation intermediates was seen in fucosidosis, and in Sandhoff, Gaucher, and Farber disease cells, whereas normal turnover rates were found in Tay-Sachs disease cells, G(M2) activator-deficient (variant AB of G(M2) gangliosidosis) and in sulfatide activator- (sap-B-) deficient cells. In G(M1) gangliosidosis and in sap precursor-deficient cells, the lysosomal glycolipid catabolism was found to be strongly retarded; accumulation of individual products could not be seen. Skin fibroblasts from patients with alpha-N-acetylgalactosaminidase deficiency (Schindler disease) cannot degrade the major blood group A glycolipid.

ABO Blood-Group System↗
PubMed1965

THE ISOLATION AND PARTIAL CHARACTERIZATION OF THE GLYCOLIPIDS OF BP8/C3H ASCITES-SARCOMA CELLS.

1. The total lipid was extracted from BP8/C3H ascites-sarcoma cells with acetone, light petroleum, pyridine and chloroform-methanol successively. Each extract was treated with mild alkali. The alkali-stable lipids from the pyridine and chloroform-methanol extracts, which included the glycolipids, were fractionated on silicic acid and silica gel G columns. 2. The total yield of glycolipid was about 60 mg./100 g. dry wt. of tumour cells, about 0.4% of the total lipid. Four classes of glycolipid were isolated and characterized as ceramide monohexoside (G1), ceramide dihexoside (G2), ceramide trihexoside (G3) and ceramide hexosaminyltrihexoside (G4). 3. G1, G2, G3 and G4 constituted 55, 21, 9 and 15% of the total glycolipid respectively. 4. G1 was a mixture of ceramide glucoside (70%) and ceramide galactoside. 5. The general structures of the oligosaccharide moieties of G2, G3 and G4 were elucidated by partial acid hydrolysis of the glycolipids with water-soluble polystyrenesulphonic acid. G2 was mostly ceramidelactoside with about 10% of ceramide galactosylgalactoside. G3 and G4 were probably a ceramide digalactosylglucoside and a ceramide N-acetylgalactosaminylgalactosylgalactosylglucoside respectively. 6. The fatty acid compositions of the glycolipids were very similar; lignoceric acid and nervonic acid were the major components and all contained monohydroxy acids in proportions varying from 10 to 25% of the total acids.

Ascites↗
PubMed1986

Production of oligosaccharide-binding monoclonal antibodies of diverse specificities by immunization with purified tumor-associated glycolipids inserted into liposomes with lipid A.

Two species of neutral glycosphingolipids purified from rat colon carcinoma tissue, isoglobotetraosylceramide [GalNAc(beta 1----3)Gal(alpha 1----3)Gal(beta 1----3)Glc(beta 1----1)Cer] and a related 6-sugar "analogue" were inserted into liposomes together with lipid A (from bacterial lipopolysaccharide) and used for immunization of mice and monoclonal antibody production. The yield of hybridomas producing glycolipid-specific antibody was 5-10% using a high-dose booster schedule with liposome-inserted glycolipid. In contrast the frequency was below 0.1% (no glycolipid-binding antibodies were found) when using the previously described method of immunizing with glycolipid coated on the surface of acid-treated S. minnesota. Monoclonal antibodies were screened on the purified glycolipids used for immunization and selected for differential reactivity to the two glycolipids. A diversity of specificities was demonstrated by binding to the purified antigens, in a thin-layer chromatogram binding assay and in binding tests to tumor and normal target cells.

Adenocarcinoma↗
PubMed1984

In vivo induction of tumor-specific immunity by glycolipid extracts of SV40-transformed cells.

Glycolipid extracts were prepared from various Syrian golden hamster cell lines, either SV40-transformed or spontaneously transformed. To detect possible SV40-TSTA activity of the glycolipid preparations, normal hamsters were inoculated with different glycolipid extracts and were subsequently challenged with an SV40 tumor-cell line. Significant immunoprotection against SV40 tumor challenge was induced with glycolipids obtained from SV40-transformed cell lines. This was expressed as complete tumor rejection or as a decrease in tumor growth rate, when compared to controls. No protective effects were induced with glycolipid extracts from spontaneously transformed cells. Results suggest that tumor-specific glycolipids synthesized in cells transformed by SV40 virus could act as tumor transplantation antigens responsible for specific tumor rejection in syngeneic hosts.

Animals↗
PubMed1995

Glycolipid acceptor specificity of a human Gal beta(1-3/1-4) GlcNAc alpha 2,3-sialyltransferase.

A human Gal beta(1-3/1-4)GlcNAc alpha 2,3-sialyltransferase, called ST-4, is a sialyltransferase involved in the in vivo biosynthesis of sialyl Lewis X (NeuNAc alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc) determinant. The ST-4 enzyme could utilize nLc4Cer (Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1'Cer) containing type 2 sugar chain, Lc4Cer (Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1'Cer) containing type 1 sugar chain, Gg4Cer (Gal beta 1-3GalNAc beta 1-3Gal beta 1-4Glc beta 1-1'Cer), and LacCer as glycolipid acceptor substrates, but not other neutral glycolipids (GalCer, GlcCer, Gb3Cer, Gg3Cer, Gb4Cer) and gangliosides (GM1a, GM2, GM3, GD1a, GD1b, and GT1b) as substrates. The order of sialic acid incorporation into glycolipids for the enzyme was nLc4Cer > Gg4Cer > Lc4Cer > LacCer. The apparent Km values of ST-4 for nLc4Cer and Gg4Cer were 0.47 and 2.5 mM, respectively. Thus, the ST-4 could efficiently utilize both nLc4Cer and Gg4Cer as glycolipid acceptor substrates in vitro, suggesting that the substrate specificity of the enzyme may be similar to that of a glycolipid sialyltransferase (SAT-3), which is defined as the enzyme that uses both nLc4Cer and Gg4Cer as glycolipid acceptor substrates.

Cell Adhesion Molecules↗
PubMed1991

Immunological recognition of larval Taenia crassiceps glycolipids by sera from parasite-infected mice.

The isolation and purification of a neutral glycolipid fraction from Taenia crassiceps metacestodes (KBS strain), harvested from both male and female NMRI mice at 70-80 days following intraperitoneal infection, revealed 24 thin-layer chromatography-designated glycolipid bands. The glycolipids were defined as ceramide mono- (n = 3), di- (n = 3), tri- (n = 4), tetra- (n = 5), and greater than tetrasaccharides (n = 9) according to their running properties as defined by thin-layer chromatography against standards of known structure. The defined glycolipids were tested for immunoreactivity with sera from noninfected and T. crassiceps-infected NMRI mice (intraperitoneal injection or implantation of 15 larvae/animal) using the enzyme-linked immunosorbent assay (ELISA) until day 33 p.i. (IgM and IgG reaction) and high-performance thin-layer chromatography (HPTLC) combined with immunostaining (IgG reaction) until day 7 p.i. ELISA-determined IgM and IgG titres were significantly elevated from day 5 p.i. Immunostaining revealed early reactivity for certain ceramide tetra- and greater than tetrasaccharides (n = 6) on day 3 p.i. From day 5 p.i. onwards, nearly all glycolipids, including ceramide mono- and disaccharides, were recognized by the sera from metacestode-challenged mice. On day 7 p.i., a total of 22 bands were serologically active; of these, a considerable number (n = 10) showed increased staining intensity. Remarkably, in many cases (10 of 20), 3 glycolipids (tetra- and greater than tetrasaccharides) were weakly recognized by mouse sera taken before infection.

Animals↗
PubMed1990

Glycolipid- and glycoprotein-based blood group A antigen expression in human thrombocytes. A1/A2 difference.

Total non-acid glycolipid fractions and total sodium dodecylsulphate (SDS) solubilized protein fractions were isolated from human thrombocytes obtained from single human donors having different blood group A1/A2 phenotypes. The blood group A glycolipid antigens were characterized by immunostaining of thin layer plates with different monoclonal anti-A antibodies. The glycoproteins carrying blood group A epitopes were identified by SDS-PAGE and Western blot analysis using a monoclonal anti-A antibody. Blood group A glycolipid antigens were found in both A1 and A2 thrombocytes but the A2 individuals expressed at least ten times less A glycolipids compared to the A1 individuals. Expression of A type 3/4 chain and small amounts of A type 1 chain glycolipids were seen in thrombocytes of both A1 and A2 individuals, while the type 2 chain A glycolipids appeared to be missing from the A2 thrombocytes. Blood group A reactive glycoproteins were only found in thrombocytes of A1 individuals and could not be detected in A2 individuals or a blood group O individual. The major blood group A glycoprotein were found as a double band migrating in the 130 kDa region.

ABO Blood-Group System↗
PubMed1988

Purification of Forssman and human blood group A glycolipids by affinity chromatography on immobilized Helix pomatia lectin.

A method for the affinity purification of intact glycolipids having nonreducing terminal alpha 1-3 linked N-acetylgalatosamine residues has been developed. This technique relies on the retention of the carbohydrate-binding specificity of immobilized Helix pomatia lectin in aqueous solutions of tetrahydrofuran. Both Forssman glycolipid and a mouse blood group A-active hexaosylceramide were bound by columns of the lectin equilibrated in a solvent containing 95% tetrahydrofuran and 5% water. After application of a step gradient of increasing water content up to 50%, the specifically bound glycolipids were eluted in solvent containing N-acetylgalactosamine. The Forssman and A-active glycolipids were similarly purified in a single chromatographic step from total lipid extracts of sheep and human type A erythrocyte stroma, respectively. Nonspecifically bound lipids and glycolipids were eluted from this column by simply increasing the water content of the eluting buffer. The extension of this method to other carbohydrate-binding proteins including lectins and monoclonal antibodies may provide a rapid purification of glycolipids based on their carbohydrate structures.

Animals↗
PubMed1987

Inhibition of ganglioside sialyltransferase activity and stimulation of neutral glycolipid exocytosis by heparin.

Heparin treatment of human teratocarcinoma cells in culture has several manifestations. Accumulation of gangliosides is greatly decreased while the content of cellular neutral glycolipids is relatively unaffected. However, synthesis of neutral glycolipids is increased and large amounts of these glycolipids are exported out of the cells into the medium. In addition, sialyltransferase activity of heparin-treated teratocarcinoma cells is significantly inhibited, accounting for the decreased cellular content of gangliosides. These studies are not intended to infer any physiological role of heparin in the regulation of glycolipid biosynthesis. However, results do show that beta-D-galactoside 2,3-sialyltransferase is a heparin-binding protein and that inhibition of the enzyme activity by heparin is linked to an alteration in the secretion of most neutral glycolipid precursors and sialyltransferase acceptors. These data suggest that in addition to its biosynthetic function, this ganglioside transferase may play a regulatory role in glycolipid secretion.

Autoradiography↗
PubMed1989

Structural and compositional difference in the neutral glycolipids between epithelial and non-epithelial tissue of the mouse small intestine.

Five major neutral glycolipids, GL-1-GL-5, were isolated from the mouse small intestine. Their structures and distribution were determined by permethylation analysis, sequential degradation with exoglycosidases and/or immunohistochemistry. The molar ratio of GL-1, GL-2, GL-3, GL-4 and Gl-5 in the whole small intestine was 1:0.04:0.03:0.42:0.02. The structures of GL-1 and GL-4 present in epithelial cells were reported previously to be glucosyl ceramide and asialo GM1, respectively (Umesaki, Y., Suzuki, A., Kasama, T., Tohyama, K., Mutai, M. and Yamakawa, T. (1981) J. Biochem. 90, 1731-1738). GL-5, also present in the epithelial cells, was fucosyl asialo GM1, and fucose was shown to be linked to terminal galactose of asialo GM1 in the manner of alpha(1-2) bond. GL-2 and GL-3, present in the residual tissue after scraping the mucosa, were determined to be globoside and Forssman glycolipid, respectively. Both globoside and Forssman glycolipid of the non-epithelial tissue had non-hydroxy fatty acid (C16-C24) in combination with sphingosine (C18) as the ceramide components, in contrast with the ceramide structures of the epithelial glycolipids, which contained alpha-hydroxy fatty acids in combination with phytosphingosine. Immunohistochemical staining using anti-glycolipid antibodies confirmed the distribution of asialo GM1 and fucosyl asialo GM1, and Forssman glycolipid in the epithelial and non-epithelial tissue, respectively.

Animals↗
PubMed1980

Structural analysis by mass spectrometry and NMR spectroscopy of the glycolipid sulfate from Halobacterium salinarium and a note on its possible function.

The major glycolipid sulfate of the extreme halophile Halobacterium salinarium was isolated and characterised mainly by mass spectrometry and NMR spectroscopy. The mass spectrum of the permethylated, desulfated and trimethylsilylated derivative showed the molecule to be a trihexosyl glycerol C20-diether with the sulfate group on the terminal hexose. A 3-position of the sulfate was indicated by the mass spectrum obtained after acetylation and trimethylsilylation (solvolysis of sulfate and replacement by a trimethylsilyl group). The NMR spectrum of the desulfated permethylated glycolipid gave conclusive evidence for the presence of one beta and two alpha anomeric protons. With the knowledge of degradation data it was possible to assign the beta signal to galactose (terminal hexose), and the alpha signals to glucose and mannose. These data together make it likely that the glycolipid sulfate is identical in structure with the glycolipid from Halobacterium cutirubrum characterised previously (M. Kates and P.W. Deroo, J. Lipid Res., 14 (1973) 438). On the basis of a suggested function of cerebroside sulfate of animal origin (identical polar end with the bacterial glycolipid: beta-galactopyranose-3-sulfate) and the present knowledge of ion transport in Halobacteria, it is proposed that the bacterial glycolipid may function as a selective K+ receptor for the K+ transport from a high-Na+ and low-K+ outside medium.

Glycolipids↗
PubMed1985

Glycolipid-binding proteins.

Proteins which bind glycolipids with high specificity are tentatively divided into two groups. One group consists of activator proteins involved in the catabolism of glycolipids by acid lysosomal hydrolases. Two activator proteins, GM2-activator and sphingolipid activator protein-1, are critically appraised on their glycolipid-binding properties and on their activity to facilitate the transfer of glycolipids. These proteins are glycoproteins localized in the lysosomes. Their molecular weights are in a range of 21 000-27 000, and isoelectric points are 4-5. Glycolipid transfer protein (GLTP) is included in the other group. GLTP purified from pig brain has a molecular weight of about 20 000 and an isoelectric point of 8.3. GLTP facilitates the transfer of various glycosphingolipids and glyceroglycolipids between membranes. The protein does not facilitate the transfer of phospholipids or cholesterol. GLTP binds galactosylceramide. The galactosylceramide-GLTP complex participates in the transfer reaction as the intermediate. Each protein in both groups binds glycolipids with a characteristic specificity to the sugar moiety. A stoichiometry of 1 mol of lipid per mol of protein has been found in all three proteins. Proteins in both groups seem to have a hydrophobic region on their surface, since all three proteins have been efficiently purified by hydrophobic chromatography.

Animals↗
PubMed1992

A ceramide analogue (PDMP) inhibits glycolipid synthesis in fish embryos.

Glycolipids were depleted from medaka embryos using 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP), an inhibitor of glucosylceramide synthetase. Embryos cultured in the presence of 20 microM PDMP exhibited a dramatic decline in glycolipid synthesis and cell surface expression. Metabolic labeling of glucosylceramide declined by 87% on Days 3-6 of development and 72% on Days 7-10 (hatching occurred on Day 10). In parallel, PDMP-treated embryos exhibited a striking loss of several tissue-specific glycolipid antigens, including 9-O-acetyl GD3 from brain and retina, GT3/GQ1C from brain, neural tube, and retina, and sulfated glycolipid from skin and gut. Despite these changes in glycolipid expression, PDMP-treated embryos were fully viable with no evidence of developmental abnormality. PDMP appears to provide a useful tool for identifying glycolipid antigens in embryos and investigating their role in development.

Animals↗
PubMed1990

Receptor-active glycolipids of epithelial cells of the small intestine of young and adult pigs in relation to susceptibility to infection with Escherichia coli K99.

Glycolipids from mucosa scrapings of small intestine of neonatal and adult pigs were tested by the thin-layer chromatogram overlay assay for the binding of Escherichia coli K99. There was practically no binding to acid or non-acid glycolipids of adult pig, known to be resistant to infection with this bacterium. However, piglets, which are susceptible to infection, showed a clear binding to a doublet band in the acid glycolipid fraction. The receptor-active glycolipid was isolated and shown by mass spectrometry, NMR spectroscopy and degradation methods to be NeuGc alpha-3Gal beta 4Glc beta Cer (NeuGc-GM3), the two bands being due to heterogeneity of the ceramide. When tested against various reference glycolipids, NeuAc-GM3 was shown to be inactive. This ganglioside was dominating in adult pig. The apparent developmental disappearance of N-glycolyl groups in glycolipids of intestinal mucosa may have a correspondence in protein-linked sequences as well as thus explain the resistance of adult pigs to infection with E. coli K99.

Aging↗