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 559 records · Page 31Linked to original sources
PubMed1994

Protective effect of some exogenous glycolipids on human cultured keratinocytes against lipid peroxidation.

Cultured human keratinocytes were incubated in the presence of glycolipids (GM1, asialoGM1, glucosylceramide and galactosylceramide) added to the medium at a concentration of 10(-5) M. All of them became associated with the cells, but in different amounts depending on the type of glycolipid and on the time in culture. GM1- and asialoGM1-treated keratinocytes developed a resistance to peroxidative stress induced by FeSO4/H2O2 treatment. These results suggest that these exogenously added glycolipids could play a role as eutrophic, repairing and protective agents for the epidermis.

Cells, Cultured↗
PubMed1983

Grafting of triggering site onto lymphocytes; distribution of grafted dinitrophenyl groups on cell surface glycoproteins and glycolipids.

Quantitative investigation of membrane-bound sialoglycoconjugates on lymphocyte surface was performed by chemical modification of the sialic acid residues with radioactive N4-dinitrophenyl-L-2,4-diaminobutyric acid hydrazide (DNP-DABH). This labeled both glycoproteins and glycolipids with concomitant preservation of the mitogenic activity by multivalent hapten binding protein (anti-DNP antibody). Under conditions where maximum stimulation of thymocytes occurred radioactive DNP-DABH labeled 1.1 X 10(7) glycolipids molecules/cell but, only 3 X 10(6) glycoproteins molecules/cell. When B lymphocytes, which do not undergo DNP-mediated stimulation were used, glycolipids labeling could not be detected. Major differences between stimulation committed and non-committed DNP-modified lymphocytes was the amount of ligand attached to the cell surface sialoglycolipids (gangliosides).

Animals↗
PubMed1996

Histo-blood group p: biosynthesis of globoseries glycolipids in EBV-transformed B cell lines.

The genetic and biosynthetic basis of the histo-blood group P-system is not fully understood. Individuals with the rare p phenotype do not express the three glycolipid antigens (Pk, P and P1) of this system, probably because of deficiencies in glycosyltransferases involved in their biosynthesis. Iiuka et al. [Iiuka S, Chen SH, Yoshida A (1986) Biochem Biophys Res Commun 137: 1187-95], however, previously reported that detergent extracts from an EBV-transformed B cell line derived from a p individual did express the glycosyltransferase activity (Pk transferase) assumed to be missing in this blood group status. Here, we have reinvestigated the antigen expression and glycosyltransferase activities in two p individuals by analysing EBV-transformed cell lines as well as erythrocytes to confirm the blood group P status. The thin layer chromatography glycolipid profile of extracts from erythrocytes and EBV-transformed B cell lines showed characteristic accumulation of lactosylceramide and absence of Pk and P antigens. Glycosyltransferase activities of the B cell lines were analysed using glycolipid substrates and both extracts were found to contain lactosylceramide synthetase and P transferase activities but to be completely devoid of Pk transferase activity. The presented data indicate that p individuals, in contrast to previous reports, do not express a functional Pk glycosyltransferase.

Antigens, Surface↗
PubMed1993

Peripheral neuropathy associated with monoclonal IgM antibody to glycolipids with a terminal glucuronyl-3-sulfate epitope.

Twenty-nine patients with paraproteinaemia, 12 with neuropathy and 17 without a previous record of neurological symptoms were clinically characterized. All 12 neuropathy patients had a moderate to severe sensorimotor demyelinating neuropathy. The patients were examined with regard to serum antibodies to gangliosides, including GM1, GD1a, GD1b, GT1b, and LM1, and other acidic glycolipids, including LK1 and sulphatide, of human brain and peripheral nerve. Sera from 80 blood donors, 40 men and 40 women 20-60 years of age, were used as normal controls. The sera were analysed with an ELISA performed on thin-layer chromatography plates. At a dilution of 1/400 none of the control sera gave a detectable reaction and a titre of > or = 1:400 was considered as a positive test. In 11 of the 12 neuropathy patients the paraproteinaemia was of IgM type and 10 of them had a positive antibody titre against LK1 and Hex-LK1, acidic glycolipids with a terminal glucuronyl-3-sulphate group. The antibody titre against LK1 in 1 patient was 1:400 and varied between 1:5,000 and 1:3,200,000 in the other 9. One of the patients also had a positive titre, 1:64,000, to sulphatide. None of the sera from the 17 paraproteinaemia patients without a previous record of neurological symptoms contained antibodies to LK1 or to any glycolipid antigen examined, except for sulphatide. A positive titre (> or = 1:400) of antibodies to sulphatide was found in sera from 4 of these patients, the titres being < or = 3,200.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Characterization of a monoclonal antibody reactive with a glycolipid antigen expressed by tumorigenic and certain immortalized, non-tumorigenic rat esophageal epithelial cell lines.

A monoclonal antibody (mAb 5G) was produced against a tumorigenic rat esophageal epithelial cell line, designated B2T. Using an enzyme-linked immunosorbent assay, immunofluorescence assay (IFA), thin-layer chromatography (TLC) and immunoperoxidase staining, it was found that mAb 5G reacted specifically with a glycolipid antigen expressed by three tumorigenic rat esophageal epithelial cell lines, and two out of the three non-tumorigenic, immortalized rat esophageal epithelial cell lines tested; but did not react with primary cultures of normal rat esophageal epithelial cells or fibroblasts. mAb 5G did not bind to rat respiratory tract carcinoma cell lines, to immortalized rat tracheal epithelial cell lines, or to primary cultures of normal rat tracheal epithelial cells. In addition, mAb 5G did not react with any of the human or mouse cell lines tested. In IFA experiments, mAb 5G stained imprints prepared from in vivo propagated B2T tumor tissues, but did not react with normal rat esophageal, tracheal, lung, liver, and kidney tissues. The antigen was identified by TLC as a neutral glycolipid, consisting of two bands, with RF = 0.45 and 0.41, which migrated in proximity to the ceramide trihexoside standard on TLC plates. Densitometric scanning of the antigen bands indicated that the tumorigenic rat esophageal cell lines possessed 50%-90% more mAb-5G-reactive antigen than the non-tumorigenic esophageal cell lines. The results show that mAb 5G reacts specifically with a glycolipid antigen expressed by tumorigenic and certain non-tumorigenic, immortalized rat esophageal epithelial cell lines that might be at the late stages of transformation and early malignancy.

Animals↗
PubMed1992

Neutral glycolipids of human and bovine milk.

The neutral glycolipids of milk, a small fraction of the total lipids, are of potential biological importance. The simultaneous quantitation of the simple (less than five sugars) glycosphingolipids of human milk samples was achieved by high-pressure liquid chromatography. The samples, representing various stages of lactation, parity of the nursing child, and age of the mother, contained similar glycolipid patterns, but with varying individual glycolipid concentrations. The cerebrosides are major glycosphingolipids of human milk: the non-hydroxylated fatty acid (NFA)-containing species are present at 1.8 microM, and the hydroxylated and/or short-chain fatty acid-containing species (HFA) are present at 1.7 microM; NFA lactosylceramide is present at 931 nM. The cerebrosides appear to be primarily galactosylceramides (galactocerebrosides); glucosylceramides (glucocerebrosides) are a minor component. Globotriaosylceramide (Gb3) is found at 50 nM and 73 nM for the NFA and HFA species, respectively, while globoside (Gb4) is found at 45 nM and 46 nM for the NFA and HFA species. Bovine milk glycosphingolipids differ from those of human milk, with bovine milk containing mainly NFA glucosylceramide (8 microM) and NFA lactosylceramide (17 microM); bovine milk contains little Gb3 or Gb4.

Animals↗
PubMed1999

Gangliosides and neutral glycolipids in ependymal, neuronal and primitive neuroectodermal tumors.

Neutral glycolipid and ganglioside compositions were determined on 11 ependymal tumors, 12 medulloblastomas, 6 other neuronal tumors of the brain, 4 peripheral neuroblastomas, 1 cerebral primitive neuroectodermal tumor (PNET), and 1 PNET of the thoracic wall. Within the group of tumors that can demonstrate neuronal phenotypes, there was an association between the degree of neuronal differentiation usually demonstrated by these tumors and the proportions of both GD1a and 1b-pathway gangliosides. The amount of globoside also correlated with the amount of 1b pathway gangliosides. Patients with medulloblastomas whose 1b gangliosides made up over 15% of the total gangliosides survived longer that those with lower proportions of 1b gangliosides. The only gangliosides in the choroid plexus papilloma were GM3 and GD1a, but other ependymal tumors had significant amounts of GD1b and its metabolic precursors. Ependymoma and anaplastic ependymoma had similar neutral glycolipid compositions, which were different from subependymoma, which lacked ceramide monohexoside and ceramide dihexoside. These differences in glycolipid compositions suggest that there may be fundamental biological differences between these types of ependymal tumors.

Adult↗
PubMed1999

Complement activation by bacterial surface glycolipids: a study with planar bilayer membranes.

Planar asymmetric glycolipid/phospholipid bilayer membranes were used as a reconstitution model of the lipid matrix of the outer membrane of Gram-negative bacteria to study complement (C) activation by various bacterial surface glycolipids with the aim of defining the C activation pathway. As glycolipids the lipopolysaccharides of Salmonella enterica serovar Minnesota R mutant strains R595 (Re LPS) and R4 (Rd2 LPS), pentaacyl lipid A from the LPS of the Escherichia coli Re mutant F515, and glycosphingolipid GSL-1 of Sphingomonas paucimobilis IAM 12576 were used. Methylester and carboxyl-reduced derivatives of GSL-1 were used to elucidate the role of the carboxyl group as common functional group of LPS and GSL-1 for C activation. The formation of lytic pores was monitored via the measurement of changes in membrane current. For all glycolipids we observed a considerable increase in membrane current soon after addition of whole human serum due to the formation of lytic pores in the membranes. Pore formation was dependent on the presence of C9, indicating that the observed current changes were due to C activation. We found that in our reconstitution system of the outer membrane lipid A, Re LPS, and Rd2 LPS activated the classical pathway, the activation being independent of specific anti-LPS antibodies. In contrast, GSL-1 and the methylester derivative of GSL-1 activated the alternative pathway even at the low serum concentrations used in this study (about 0.2% v/v). Interestingly, the carboxyl reduced GSL-1 activated the classical pathway.

Antibodies↗
PubMed2006

Discovery of Pseudozyma rugulosa NBRC 10877 as a novel producer of the glycolipid biosurfactants, mannosylerythritol lipids, based on rDNA sequence.

The search for a novel producer of glycolipid biosurfactants, mannosylerythritol lipids (MEL) was undertaken based on the analysis of ribosomal DNA sequences on the yeast strains of the genus Pseudozyma. Pseudozyma rugulosa NBRC 10877 was found to produce a large amount of glycolipids from soybean oil. Fluorescence microscopic observation also demonstrated that the strain significantly accumulates polar lipids in the cells. The structure of the glycolipids produced by the strain was analyzed by (1)H and (13)C nuclear magnetic resonance and gas chromatography-mass spectrometry methods, and was determined to be the same as MEL produced by Pseudozyma antarctica, a well-known MEL producer. The major fatty acids of the present MEL consisted of C8 and C10 acids. Based on high performance liquid chromatography, the composition of the produced MEL was as follows: MEL-A (68%), MEL-B (12%), and MEL-C (20%). To enhance the production of MEL by the novel strain, factors affecting the production, such as carbon and nitrogen sources, were further examined. Soybean oil and sodium nitrate were the best carbon and nitrogen sources, respectively. The supplementation of a MEL precursor, such as erythritol, drastically enhanced the production yield from soybean oil at a rate of 70 to 90%. Under the optimal conditions in a shake culture, a maximum yield, productivity, and yield coefficient (on a weight basis to soybean oil supplied) of 142 g l(-1), 5.0 g l(-1) day(-1), and 0.5 g g(-1) were achieved by intermittent feeding of soybean oil and erythritol using the yeast.

Basidiomycota↗
PubMed2005

6-O-sulfo sialylparagloboside and sialyl Lewis X neo-glycolipids containing lactamized neuraminic acid: synthesis and antigenic reactivity against G159 monoclonal antibody.

Synthesis and antigenic reactivity of 6-O-sulfo sialylparagloboside (SPG) and sialyl Lewis X (sLeX) neo-glycolipids containing lactamized neuraminic acid are described. The suitably protected GlcNAc-beta (1-->3)-Gal-beta (1-->4)-GlcOSE derivative was glycosylated with NeuTFAc-alpha (2-->3)-Gal imidate to give NeuTFAc-alpha (2-->3)-Galbeta (1-->4)-GlcNAc-beta (1-->3)-Gal-beta (1-->4)-GlcOSE pentasaccharide. The partial N,O-deacylation in the NeuTFAc-alpha (2-->3)-Gal part afforded N-deacetylated SPG derivative which was converted to the desired oligosaccharide containing lactamized neuraminic acid. Similar treatment of the sLeX hexasaccharide derivative, NeuTFAc-alpha (2-->3)-Gal-beta (1-->4) [Fuc-alpha (1-->3)]-GlcNAc-beta (1-->3)-Gal-beta (1-->4)-GlcOSE, gave the key hexasaccharide intermediate containing lactamized neuraminic acid. These suitably protected SPG and sLex oligosaccharides were converted stepwise into the desired neo-glycolipids (GSC-551 and GSC-552) by the coupling with 2-(tetradecyl)hexadecanol, 6-O-sulfation at C-6 of the GlcNAc residure, and complete deprotection. Both lactamized-sialyl 6-O-sulfo SPG (GSC-551) and sLex (GSC-552) neo-glycolipids were clearly recognized with G159 monoclonal antibody showing that both the lactamized neuraminic acid and the 6-O-sulfate at C-6 of GlcNAc would be involved in the G159-defined determinant. However, the Fuc residue and the lipophilic (ceramide) part may not be critical for this recognition.

Antibodies, Monoclonal↗
PubMed1999

Separation and determination of glycolipids from edible plant sources by high-performance liquid chromatography and evaporative light-scattering detection.

Glycolipids from edible plant sources were accurately quantified by silica-based, normal-phase high-performance liquid chromatography using an evaporative light-scattering detector. Five major glycolipid classes (acylated steryl glucoside, steryl glucoside, ceramide monohexoside, monogalactosyldiacylglycerol, and digalactosyldiacylglycerol) were separated and determined with a binary gradient system consisting of chloroform and methanol/water (95:5, vol/vol) without any interference from other lipid classes and pigments. The described method was applied to 48 edible plants available in Japan including cereals, legumes, vegetables, and fruits. Examined plant species contained glycolipids in wide concentration ranges, such as 5-645 mg/100 g tissue.

Ceramides↗
PubMed1985

Solid-phase radiolabeling of glycolipids with galactose oxidase and sodium boro[3H]hydride.

Neutral glycosphingolipids immobilized on plastic surfaces were specifically radiolabeled with the galactose oxidase-sodium boro[3H]hydride method. Glycolipids could be immobilized in the absence of any other lipids such as phosphatidylcholine and cholesterol. Rather, the presence of these lipid components decreased the efficiency of radiolabeling. Glycolipids having more than four carbohydrate moieties with terminal galactosyl residues were effectively radiolabeled and could be easily recovered by elution from the plastic with ethanol in one step. This method will be suitable for analysis of small samples of "upper-phase" neutral glycolipids having terminal galactose or N-acetylgalactosamine.

Animals↗
PubMed1992

Quantitative derivatization and high-performance liquid chromatographic analysis of cyanobacterial heterocyst-type glycolipids.

Procedures are described for the rapid and quantitative analysis of cyanobacterial heterocyst-type glycolipids (HGs) by normal-phase HPLC of their per-O-benzoylated derivatives. Total lipids are obtained from 1 ml of nitrogen-fixing cyanobacterial culture by triplicate extraction with chloroform/methanol, 1/1 (v/v), and the HGs are isolated from other complex lipids by preparative silica gel TLC. A C18 solid-phase extraction cartridge is used to ensure quantitative salt-free recovery of the HGs, and the purified glycolipids are then rendered uv-absorbing by a per-O-benzoylation derivatization reaction for which optimal conditions have been established. Derivatives are analyzed within 12 min on a 3-microns silica HPLC column using a linear gradient of 2-propanol in n-hexane and uv monitoring at 230 nm. The reaction product was also used to determine the relative proportions of the glucosyl and galactosyl epimers of individual members of this class of glycolipid.

Chromatography, High Pressure Liquid↗
PubMed1977

Specific interaction of concanavalin A with glycolipid monolayers.

The effect of 131I-labelled concanavalin A on the surface pressure and surface radioactivity of monolayers formed from phospholipids and from natural and synthetic glycolipids has been studied. The lectin binds to and penetrates dipalmitoyl phosphatidylcholine monolayers at a surface pressure of 15 dynes/cm and this interaction is inhibited by the presence of alpha-methyl mannose in the subphase. At surface pressures of 25 dynes/cm or higher, concanavalin A will interact with monoglucosyl diglyceride or diglucosyl diglyceride from Acholeplasma laidlawii and with synthetic glycolipids containing 2 or 3 alpha 1 leads to 4-linked D-glucose residues in the headgroup, but not with phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, or with the ganglioside II3NeuAc-GgOse4-Cer. The binding to the glycolipid sugar group and penetration of the hydrocarbon region seem to occur simultaneously, as the time courses for the development of surface pressure and surface radioactivity coincide.

Cell Membrane↗
PubMed1975

Blood group A active difucosyl glycolipid from hog gastric mucosa.

A new difucosyl glycolipid exhibiting blood group A activity was isolated from water-soluble glycolipid fraction of hog gastric mucosa. The structure of this glycolipid was identified by partial acid hydrolysis, sequential degradation with specific glycosidases and methylation analysis, as: "see article".

ABO Blood-Group System↗
PubMed1977

Glycolipid intermediates involved in the transfer of N-acetylglucosamine to endogenous proteins in a yeast membrane preparation.

A particulate membrane fraction from Saccharomyces cerevisiae contains transferases which catalyze the incorporation of N-acetylglucosamine from UDP-N-acetylglucosamine into a lipid fraction as well as into a protein fraction. The lipid fraction contains two alkali-stable lipids which can be separated on a silica G-60 column. The sugar moieties of these polyprenoid lipids are: N-acetylglucosamine and di-N-acetylchitobiose. The transfer of carbohydrate from isolated glycolipids to endogenous protein has been examined. After separation of protein and saccharide by hydrazinolysis and reacetylation only di-N-acetylchitobiose is found, and also when glycolipid containing only one N-acetylglucosamine is used as substrate. Maximum transfer of saccharides from glycolipids to protein is obtained at a Triton X-100 concentration of 1%. At this Triton X-100 concentration there is practically no transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to the phosphorylated lipid. Therefore, when polyprenyl diphosphate N-acetyl[3H]-glucosamine is incubated together with UDP-N-acetyl[14C]glucosamine with the membrane fraction in the presence of 1% Triton X-100, a doubly labelled di-N-acetylchitobiose linked to lipid is formed with N-acetyl[14C]glucosamine at the non-reducing end of the chain.

Acetylglucosamine↗
PubMed1980

Alk-1-enyl ether phospholipids (plasmalogens) and glycolipids of Treponema hyodysenteriae. Analysis of acyl and alk-1-enyl moieties.

The lipids of Treponema hyodysenteriae B78, the etiologic agent of swine dysentery, comprised 16.4% of the cell dry weight, and consisted of 37.4% glycolipids, 28.6% phospholipids, and 34.0% neutral lipids. Monogalactosyldiacylglycerol, a major lipid in all Treponema except Treponema pallidum, comprised 80% of the glycolipids. An unidentified galactolipid less polar than monogalactosyldiacylglycerol was also detected. Phosphatidylglycerol (19.5% of the total lipids) was the major phospholipid. Phosphatidylcholine, characteristically the major phospholipid of treponemes, comprised 6.1% of the total lipids. Cardiolipin and lysophosphatidylcholine were minor components. The alk-1-enyl ether forms of both the phospholipids (plasmalogens) and glycolipids predominated. The alk-1-enyl ether forms of monogalactosyldiacylglycerol, the unidentified galactolipid, phosphatidylglycerol, cardiolipin, and phosphatidylcholine were 88.3, 96.4, 74.8, 60.6, and 6.3%, respectively. The acyl and alk-1-enyl chains of the organism were qualitatively similar and differed dramatically from those of the medium indicating a capability for fatty acid synthesis that most Treponema do not possess. Saturated C14, C15, and C16 chains comprised more than 95% of the acyl and alk-1-enyl groups. About 25% of the chains were iso-15:0, anteiso-15:0, and other branched moieties.

Fatty Acids↗