Glycolipids: Any compound containing one or more monosaccharide residues bound by a glycosidic linkage to a hydrophobic moiety such as an acylglycerol (see GLYCERIDES), a sphingoid, a ceramide (CERAMIDES) (N-acylsphingoid) or a prenyl phosphate. (From IUPAC's webpage)Glycosphingolipids: Lipids containing at least one monosaccharide residue and either a sphingoid or a ceramide (CERAMIDES). They are subdivided into NEUTRAL GLYCOSPHINGOLIPIDS comprising monoglycosyl- and oligoglycosylsphingoids and monoglycosyl- and oligoglycosylceramides; and ACIDIC GLYCOSPHINGOLIPIDS which comprises sialosylglycosylsphingolipids (GANGLIOSIDES); SULFOGLYCOSPHINGOLIPIDS (formerly known as sulfatides), glycuronoglycosphingolipids, and phospho- and phosphonoglycosphingolipids. (From IUPAC's webpage)Chromatography, Thin Layer: Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Globosides: Glycosphingolipids containing N-acetylglucosamine (paragloboside) or N-acetylgalactosamine (globoside). Globoside is the P antigen on erythrocytes and paragloboside is an intermediate in the biosynthesis of erythrocyte blood group ABH and P 1 glycosphingolipid antigens. The accumulation of globoside in tissue, due to a defect in hexosaminidases A and B, is the cause of Sandhoff disease.Sulfoglycosphingolipids: GLYCOSPHINGOLIPIDS with a sulfate group esterified to one of the sugar groups.Carbohydrate Sequence: The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.Gangliosides: A subclass of ACIDIC GLYCOSPHINGOLIPIDS. They contain one or more sialic acid (N-ACETYLNEURAMINIC ACID) residues. Using the Svennerholm system of abbrevations, gangliosides are designated G for ganglioside, plus subscript M, D, or T for mono-, di-, or trisialo, respectively, the subscript letter being followed by a subscript arabic numeral to indicated sequence of migration in thin-layer chromatograms. (From Oxford Dictionary of Biochemistry and Molecular Biology, 1997)Cerebrosides: Neutral glycosphingolipids that contain a monosaccharide, normally glucose or galactose, in 1-ortho-beta-glycosidic linkage with the primary alcohol of an N-acyl sphingoid (ceramide). In plants the monosaccharide is normally glucose and the sphingoid usually phytosphingosine. In animals, the monosaccharide is usually galactose, though this may vary with the tissue and the sphingoid is usually sphingosine or dihydrosphingosine. (From Oxford Dictionary of Biochemistry and Molecular Biology, 1st ed)Lactosylceramides: Glycosphingolipids which contain as their polar head group a lactose moiety bound in glycosidic linkage to the hydroxyl group of ceramide. Their accumulation in tissue, due to a defect in lactosylceramide beta-galactosidase, is the cause of lactosylceramidosis.Carbohydrate Conformation: The characteristic 3-dimensional shape of a carbohydrate.Forssman Antigen: A glycolipid, cross-species antigen that induces production of antisheep hemolysin. It is present on the tissue cells of many species but absent in humans. It is found in many infectious agents.Galactolipids: A group of GLYCOLIPIDS in which the sugar group is GALACTOSE. They are distinguished from GLYCOSPHINGOLIPIDS in lacking nitrogen. They constitute the majority of MEMBRANE LIPIDS in PLANTS.Galactosylceramides: Cerebrosides which contain as their polar head group a galactose moiety bound in glycosidic linkage to the hydroxyl group of ceramide. Their accumulation in tissue, due to a defect in beta-galactosidase, is the cause of galactosylceramide lipidosis or globoid cell leukodystrophy.Carbohydrates: The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES. Carbohydrates are composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n.Glucosylceramides: Cerebrosides which contain as their polar head group a glucose moiety bound in glycosidic linkage to the hydroxyl group of ceramides. Their accumulation in tissue, due to a defect in beta-glucosidase, is the cause of Gaucher's disease.Spectrometry, Mass, Fast Atom Bombardment: A mass spectrometric technique that is used for the analysis of a wide range of biomolecules, such as glycoalkaloids, glycoproteins, polysaccharides, and peptides. Positive and negative fast atom bombardment spectra are recorded on a mass spectrometer fitted with an atom gun with xenon as the customary beam. The mass spectra obtained contain molecular weight recognition as well as sequence information.Trihexosylceramides: Glycosphingolipids which contain as their polar head group a trisaccharide (galactose-galactose-glucose) moiety bound in glycosidic linkage to the hydroxyl group of ceramide. Their accumulation in tissue, due to a defect in ceramide trihexosidase, is the cause of angiokeratoma corporis diffusum (FABRY DISEASE).ABO Blood-Group System: The major human blood type system which depends on the presence or absence of two antigens A and B. Type O occurs when neither A nor B is present and AB when both are present. A and B are genetic factors that determine the presence of enzymes for the synthesis of certain glycoproteins mainly in the red cell membrane.Trisaccharides: Oligosaccharides containing three monosaccharide units linked by glycosidic bonds.Chromatography, Gas: Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.Fatty Acids: Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)Blood Group Antigens: Sets of cell surface antigens located on BLOOD CELLS. They are usually membrane GLYCOPROTEINS or GLYCOLIPIDS that are antigenically distinguished by their carbohydrate moieties.Glycoconjugates: Carbohydrates covalently linked to a nonsugar moiety (lipids or proteins). The major glycoconjugates are glycoproteins, glycopeptides, peptidoglycans, glycolipids, and lipopolysaccharides. (From Biochemical Nomenclature and Related Documents, 2d ed; From Principles of Biochemistry, 2d ed)Galactose: An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. Deficiency of galactosyl-1-phosphate uridyltransferase (GALACTOSE-1-PHOSPHATE URIDYL-TRANSFERASE DEFICIENCY DISEASE) causes an error in galactose metabolism called GALACTOSEMIA, resulting in elevations of galactose in the blood.Lewis Blood-Group System: A group of dominantly and independently inherited antigens associated with the ABO blood factors. They are glycolipids present in plasma and secretions that may adhere to the erythrocytes. The phenotype Le(b) is the result of the interaction of the Le gene Le(a) with the genes for the ABO blood groups.Oligosaccharides: Carbohydrates consisting of between two (DISACCHARIDES) and ten MONOSACCHARIDES connected by either an alpha- or beta-glycosidic link. They are found throughout nature in both the free and bound form.G(M1) Ganglioside: A specific monosialoganglioside that accumulates abnormally within the nervous system due to a deficiency of GM1-b-galactosidase, resulting in GM1 gangliosidosis.Galactosyltransferases: Enzymes that catalyze the transfer of galactose from a nucleoside diphosphate galactose to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.-.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.Membrane Lipids: Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.Antigens, CD1d: A major histocompatibily complex class I-like protein that plays a unique role in the presentation of lipid ANTIGENS to NATURAL KILLER T-CELLS.FucoseMagnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).G(M3) Ganglioside: A ganglioside present in abnormally large amounts in the brain and liver due to a deficient biosynthetic enzyme, G(M3):UDP-N-acetylgalactosaminyltransferase. Deficiency of this enzyme prevents the formation of G(M2) ganglioside from G(M3) ganglioside and is the cause of an anabolic sphingolipidosis.Antigens, CD1: Glycoproteins expressed on cortical thymocytes and on some dendritic cells and B-cells. Their structure is similar to that of MHC Class I and their function has been postulated as similar also. CD1 antigens are highly specific markers for human LANGERHANS CELLS.Sialic Acids: A group of naturally occurring N-and O-acyl derivatives of the deoxyamino sugar neuraminic acid. They are ubiquitously distributed in many tissues.Antigens, CD15: A trisaccharide antigen expressed on glycolipids and many cell-surface glycoproteins. In the blood the antigen is found on the surface of NEUTROPHILS; EOSINOPHILS; and MONOCYTES. In addition, CD15 antigen is a stage-specific embryonic antigen.Ceramides: Members of the class of neutral glycosphingolipids. They are the basic units of SPHINGOLIPIDS. They are sphingoids attached via their amino groups to a long chain fatty acyl group. They abnormally accumulate in FABRY DISEASE.G(M2) Ganglioside: A glycosphingolipid that accumulates due to a deficiency of hexosaminidase A or B (BETA-N-ACETYLHEXOSAMINIDASES), or GM2 activator protein, resulting in GANGLIOSIDOSES, heredity metabolic disorders that include TAY-SACHS DISEASE and SANDHOFF DISEASE.Monosaccharides: Simple sugars, carbohydrates which cannot be decomposed by hydrolysis. They are colorless crystalline substances with a sweet taste and have the same general formula CnH2nOn. (From Dorland, 28th ed)P Blood-Group System: A blood group related to the ABO, Lewis and I systems. At least five different erythrocyte antigens are possible, some very rare, others almost universal. Multiple alleles are involved in this blood group.Sphingomonas: A genus of gram-negative, aerobic, rod-shaped bacteria characterized by an outer membrane that contains glycosphingolipids but lacks lipopolysaccharide. They have the ability to degrade a broad range of substituted aromatic compounds.Phospholipids: Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.Glycosylphosphatidylinositols: Compounds containing carbohydrate or glycosyl groups linked to phosphatidylinositols. They anchor GPI-LINKED PROTEINS or polysaccharides to cell membranes.Mycobacterium marinum: A moderate-growing, photochromogenic species found in aquariums, diseased fish, and swimming pools. It is the cause of cutaneous lesions and granulomas (swimming pool granuloma) in humans. (Dorland, 28th ed)Natural Killer T-Cells: A specialized subset of T-LYMPHOCYTES that exhibit features of INNATE IMMUNITY similar to that of NATURAL KILLER CELLS. They are reactive to glycolipids presented in the context of the major histocompatibility complex (MHC) class I-like molecule, CD1D ANTIGEN.Gas Chromatography-Mass Spectrometry: A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.I Blood-Group System: A blood group related both to the ABO and P systems that includes several different antigens found in most people on erythrocytes, in milk, and in saliva. The antibodies react only at low temperatures.Lipids: A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)Galactose Oxidase: An enzyme that oxidizes galactose in the presence of molecular oxygen to D-galacto-hexodialdose. It is a copper protein. EC 1.1.3.9.Gangliosidoses: A group of autosomal recessive lysosomal storage disorders marked by the accumulation of GANGLIOSIDES. They are caused by impaired enzymes or defective cofactors required for normal ganglioside degradation in the LYSOSOMES. Gangliosidoses are classified by the specific ganglioside accumulated in the defective degradation pathway.PolysaccharidesGlycosyltransferases: Enzymes that catalyze the transfer of glycosyl groups to an acceptor. Most often another carbohydrate molecule acts as an acceptor, but inorganic phosphate can also act as an acceptor, such as in the case of PHOSPHORYLASES. Some of the enzymes in this group also catalyze hydrolysis, which can be regarded as transfer of a glycosyl group from the donor to water. Subclasses include the HEXOSYLTRANSFERASES; PENTOSYLTRANSFERASES; SIALYLTRANSFERASES; and those transferring other glycosyl groups. EC 2.4.Sulfuric Acids: Inorganic and organic derivatives of sulfuric acid (H2SO4). The salts and esters of sulfuric acid are known as SULFATES and SULFURIC ACID ESTERS respectively.Mannose: A hexose or fermentable monosaccharide and isomer of glucose from manna, the ash Fraxinus ornus and related plants. (From Grant & Hackh's Chemical Dictionary, 5th ed & Random House Unabridged Dictionary, 2d ed)HexosaminesHalobacteriaceae: A family of extremely halophilic archaea found in environments with high salt concentrations, such as salt lakes, evaporated brines, or salted fish. Halobacteriaceae are either obligate aerobes or facultative anaerobes and are divided into at least twenty-six genera including: HALOARCULA; HALOBACTERIUM; HALOCOCCUS; HALOFERAX; HALORUBRUM; NATRONOBACTERIUM; and NATRONOCOCCUS.N-Acetylneuraminic Acid: An N-acyl derivative of neuraminic acid. N-acetylneuraminic acid occurs in many polysaccharides, glycoproteins, and glycolipids in animals and bacteria. (From Dorland, 28th ed, p1518)Periodic Acid: A strong oxidizing agent.Neutral Glycosphingolipids: A subclass of GLYCOSPHINGOLIPIDS containing one or more sugars within their head group connected directly to a ceramide moiety. They consist of monoglycosyl-, and oligoglycosylsphingoids and monoglycosyl- and oligoglycosylceramides.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Glyceryl Ethers: Compounds in which one or more of the three hydroxyl groups of glycerol are in ethereal linkage with a saturated or unsaturated aliphatic alcohol; one or two of the hydroxyl groups of glycerol may be esterified. These compounds have been found in various animal tissue.Sphingolipids: A class of membrane lipids that have a polar head and two nonpolar tails. They are composed of one molecule of the long-chain amino alcohol sphingosine (4-sphingenine) or one of its derivatives, one molecule of a long-chain acid, a polar head alcohol and sometimes phosphoric acid in diester linkage at the polar head group. (Lehninger et al, Principles of Biochemistry, 2nd ed)Phosphatidylinositols: Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to the hexahydroxy alcohol, myo-inositol. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid, myo-inositol, and 2 moles of fatty acids.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.Fucosyltransferases: Enzymes catalyzing the transfer of fucose from a nucleoside diphosphate fucose to an acceptor molecule which is frequently another carbohydrate, a glycoprotein, or a glycolipid molecule. Elevated activity of some fucosyltransferases in human serum may serve as an indicator of malignancy. The class includes EC 2.4.1.65; EC 2.4.1.68; EC 2.4.1.69; EC 2.4.1.89.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Lectins: Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.Ustilaginales: An order of basidiomycetous fungi; some species are parasitic on grasses (POACEAE) and maize.Chemistry: A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.Sialyltransferases: A group of enzymes with the general formula CMP-N-acetylneuraminate:acceptor N-acetylneuraminyl transferase. They catalyze the transfer of N-acetylneuraminic acid from CMP-N-acetylneuraminic acid to an acceptor, which is usually the terminal sugar residue of an oligosaccharide, a glycoprotein, or a glycolipid. EC 2.4.99.-.Chemical Phenomena: The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.TrehaloseAcholeplasma laidlawii: An organism originally isolated from sewage, manure, humus, and soil, but recently found as a parasite in mammals and birds.Cord Factors: Toxic glycolipids composed of trehalose dimycolate derivatives. They are produced by MYCOBACTERIUM TUBERCULOSIS and other species of MYCOBACTERIUM. They induce cellular dysfunction in animals.Neuraminic AcidsAcetylgalactosamine: The N-acetyl derivative of galactosamine.Erythrocytes: Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.Glycosides: Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and nonsugar component (aglycone) are formed. (From Dorland, 28th ed; From Miall's Dictionary of Chemistry, 5th ed)Adhesins, Escherichia coli: Thin, filamentous protein structures, including proteinaceous capsular antigens (fimbrial antigens), that mediate adhesion of E. coli to surfaces and play a role in pathogenesis. They have a high affinity for various epithelial cells.Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization: A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.Hemadsorption Inhibition Tests: Serological tests that measure anti-hemadsorption agents such as antiviral ANTIBODIES that block VIRAL HEMAGGLUNININS from adhering to the surface of red blood cells.Disaccharides: Oligosaccharides containing two monosaccharide units linked by a glycosidic bond.Methylation: Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)Cell Wall: The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.Chloroform: A commonly used laboratory solvent. It was previously used as an anesthetic, but was banned from use in the U.S. due to its suspected carcinogenicity.Mycolic Acids

A genetic model of substrate deprivation therapy for a glycosphingolipid storage disorder. (1/2592)

Inherited defects in the degradation of glycosphingolipids (GSLs) cause a group of severe diseases known as GSL storage disorders. There are currently no effective treatments for the majority of these disorders. We have explored a new treatment paradigm, substrate deprivation therapy, by constructing a genetic model in mice. Sandhoff's disease mice, which abnormally accumulate GSLs, were bred with mice that were blocked in their synthesis of GSLs. The mice with simultaneous defects in GSL synthesis and degradation no longer accumulated GSLs, had improved neurologic function, and had a much longer life span. However, these mice eventually developed a late-onset neurologic disease because of accumulation of another class of substrate, oligosaccharides. The results support the validity of the substrate deprivation therapy and also highlight some limitations.  (+info)

Crystal structure of an MHC class I presented glycopeptide that generates carbohydrate-specific CTL. (2/2592)

T cell receptor (TCR) recognition of nonpeptidic and modified peptide antigens has been recently uncovered but is still poorly understood. Immunization with an H-2Kb-restricted glycopeptide RGY8-6H-Gal2 generates a population of cytotoxic T cells that express both alpha/beta TCR, specific for glycopeptide, and gamma/delta TCR, specific for the disaccharide, even on glycolipids. The crystal structure of Kb/RGY8-6H-Gal2 now demonstrates that the peptide and H-2Kb structures are unaffected by the peptide glycosylation, but the central region of the putative TCR binding site is dominated by the extensive exposure of the tethered carbohydrate. These features of the Kb/RGY8-6H-Gal2 structure are consistent with the individual ligand binding preferences identified for the alpha/beta and gamma/delta TCRs and thus explain the generation of a carbohydrate-specific T cell response.  (+info)

Cryptosporidium parvum sporozoite pellicle antigen recognized by a neutralizing monoclonal antibody is a beta-mannosylated glycolipid. (3/2592)

The protozoan parasite Cryptosporidium parvum is an important cause of diarrhea in humans, calves, and other mammals worldwide. No approved vaccines or parasite-specific drugs are currently available for the control of cryptosporidiosis. To effectively immunize against C. parvum, identification and characterization of protective antigens are required. We previously identified CPS-500, a conserved, neutralization-sensitive antigen of C. parvum sporozoites and merozoites defined by monoclonal antibody 18.44. In the present study, the biochemical characteristics and subcellular location of CPS-500 were determined. CPS-500 was chloroform extractable and eluted with acetone and methanol in silicic acid chromatography, consistent with being a polar glycolipid. Following chloroform extraction and silicic acid chromatography, CPS-500 was isolated by high-pressure liquid chromatography for glycosyl analysis, which indicated the presence of mannose and inositol. To identify which component of CPS-500 comprised the neutralization-sensitive epitope recognized by 18.44, the ability of the monoclonal antibody to bind CPS-500 treated with proteases, or with alpha- or beta-glycosidases, was determined. Monoclonal antibody 18.44 did not bind antigen treated with beta-D-mannosidase but did bind antigen treated with alpha-D-mannosidase, other alpha- or beta-glycosidases, or a panel of proteases. These data indicated that the target epitope was dependent on terminal beta-D-mannopyranosyl residues. By immunoelectron microscopy, 18.44 binding was localized to the pellicle and an intracytoplasmic tubulovesicular network in sporozoites. Monoclonal antibody 18.44 also bound to antigen deposited and released onto substrate over the course travelled by gliding sporozoites and merozoites. Surface localization, adhesion and release during locomotion, and neutralization sensitivity suggest that CPS-500 may be involved in motility and invasion processes of the infective zoite stages.  (+info)

Gas-liquid chromatography of the heptafluorobutyrate derivatives of the O-methyl-glycosides on capillary columns: a method for the quantitative determination of the monosaccharide composition of glycoproteins and glycolipids. (4/2592)

We have developed a method involving the formation of hepta-fluorobutyrate derivatives of O-methyl-glycosides liberated from glycoproteins and glycolipids following methanolysis. The stable derivatives of the most common monosaccharides of these glycoconjugates (Ara, Rha, Xyl, Fuc, Gal, Man, Glc, GlcNAc, GalNAc, Neu5Ac, KDN) can be separated and quantitatively and reproducibly determined with a high degree of sensitivity level (down to 25 pmol) in the presence of lysine as an internal standard. The GlcNAc residue bound to Asn in N-glycans is quantitatively recovered as two peaks. The latter were easily distinguished from the other GlcNAc residues of N-glycans, thus allowing a considerable improvement of the data on structure of N-glycans obtained from a single carbohydrate analysis. The most common contaminants present in buffers commonly used for the isolation of soluble or membrane-bound glycoproteins (SDS, Triton X-100, DOC, TRIS, glycine, and polyacrylamide or salts, as well as monosaccharide constituents of proteoglycans or degradation products of nucleic acids) do not interfere with these determinations. A carbohydrate analysis of glycoproteins isolated from a SDS/PAGE gel or from PDVF membranes can be performed on microgram amounts without significant interferences. Since fatty acid methyl esters and sphingosine derivatives are separated from the monosaccharide peaks, the complete composition of gangliosides can be achieved in a single step starting from less than 1 microg of the initial compound purified by preparative Silicagel TLC. Using electron impact ionization mass spectrometry, reporter ions for the different classes of O-methyl-glycosides (pentoses, deoxy-hexoses, hexoses, hexosamines, uronic acids, sialic acid, and KDN) allow the identification of these compounds in very complex mixtures. The mass of each compound can be determined in the chemical ionization mode and detection of positive or negative ions. This method presents a considerable improvement compared to those using TMS derivatives. Indeed the heptafluorobutyrate derivatives are stable, and acylation of amino groups is complete. Moreover, there is no interference with contaminants and the separation between fatty acid methyl-esters and O-methyl glycosides is achieved.  (+info)

Formation of lipid-linked sugar compounds in Halobacterium salinarium. Presumed intermediates in glycoprotein synthesis. (5/2592)

The ability of bacitracin to inhibit the growth of Halobacterium salinarium suggested that glycosylation of the major envelope component, a high molecular weight glycoprotein, might occur via a pathway involving lipid intermediates. This report demonstrates that the cells have enzymatic activities for formation of lipid-linked sugar compounds having the expected properties of such intermediates. Whole cell homogenate catalyzed the transfer of sugar from UDP-glucose, GDP-mannose, and UDP-N-acetyglucosamine to endogenous lipid acceptors. Two lipid products were formed from UDP-glucose, two from GDP-mannose, and one from UDP-N-acetylglucosamine. Characterization of the partially purified lipids by ion exchange chromatography, thin layer chromatography, and mild acid and base hydrolysis showed the major product in each case to have the properties expected for polyisoprenyl phosphoglucose, polyisoprenyl phosphomannose, and polyisoprenyl pyrophospho-N-acetylglucosamine. Estimates of chain length by thin layer chromatography indicate that the lipid has 11 to 12 isoprene identity as a C55-60-polyisoprenyl pyrophospho-N-acetylglucosamine. The N-acetylglucosamine transferase, present in cell envelope preparations, was partially characterized. The enzyme was found to be extremely halophilic, specifically requiring a high concentration of KCl. Optimum activity was obtained at 4 m KCl and partial substitution of K+ by Na+ resulted in a decrease in activity.  (+info)

Isolation and characterization of two mouse L cell lines resistant to the toxic lectin ricin. (6/2592)

Two variant mouse L cell lines (termed CL 3 and CL 6) have been selected for resistant to ricin, a galactose-binding lectin with potent cytotoxic activity. The resistant lines exhibit a 50 to 70% decrease in ricin binding and a 300- to 500-fold increase in resistance to the toxic effects of ricin. Crude membrane preparations of CL 3 cells have increased sialic acid content (200% of control), while the galactose, mannose, and hexosamine content is within normal limits. Both the glycoproteins and glycolipids of CL 3 cells have increased sialic acid, with the GM3:lactosylceramide ratios for parent L and CL 3 cells being 0.29 and 1.5, respectively. In contrast, the membranes of CL 6 cells have a decrease in sialic acid, galactose, and hexosamine content with mannose being normal. Both cell lines have specific alterations in glycosyltransferase activities which can account for the observed membrane sugar changes. CL 3 cells have increased CMP-sialic acid:glycoprotein sialyltransferase and GM3 synthetase activities, while CL 6 cells have decrease UDP-GlcNAc:glycoproteinN-acetylglucosaminyltransferase and DPU-galactose:glycoprotein galactosyltransferase activities. The increased sialic acid content of CL 3 cells serves to mask ricin binding sites, since neuraminidase treatment of this cell line restores ricin binding to essentially normal levels. However, the fact that neuraminidase-treated CL 3 cells are still 45-fold resistant to ricin indicates that either a special class of productive ricin binding sites is not being exposed or that the cell line has a second mechanism for ricin resistance.  (+info)

Participation of a trisaccharide-lipid in glycosylation of oviduct membrane glycoproteins. (7/2592)

Preincubation of a hen oviduct membrane preparation with UDP-Nactyl[14C]glucosamine and bacitracin, followed by incubation with GDP-mannose, leads to formation of a chloroform/methanol (2/1)-extractable glycolipid. Treatment of the lipid with mild acid results in the release of a trisaccharide shown to have the structure beta-mannosyl-N-acetylglucosamineyl-N-acetylglucosamine. Incubation of purified trisaccharide-lipid with oviduct membranes in the presence of sodium deoxycholate, Mn2+, and GDP-mannose leads to formation of a labeled glycoprotein with an apparent molecular weight of 25,000...  (+info)

A fluorescence resonance energy transfer approach for monitoring protein-mediated glycolipid transfer between vesicle membranes. (8/2592)

A lipid transfer protein, purified from bovine brain (23.7 kDa, 208 amino acids) and specific for glycolipids, has been used to develop a fluorescence resonance energy transfer assay (anthrylvinyl-labeled lipids; energy donors and perylenoyl-labeled lipids; energy acceptors) for monitoring the transfer of lipids between membranes. Small unilamellar vesicles composed of 1 mol% anthrylvinyl-galactosylceramide, 1.5 mol% perylenoyl-triglyceride, and 97.5% 1-palmitoyl-2-oleoyl phosphatidylcholine (POPC) served as donor membranes. Acceptor membranes were 100% POPC vesicles. Addition of glycolipid transfer protein to mixtures of donor and acceptor vesicles resulted in increasing emission intensity of anthrylvinyl-galactosylceramide and decreasing emission intensity of the nontransferable perylenoyl-triglyceride as a function of time. The behavior was consistent with anthrylvinyl-galactosylceramide being transferred from donor to acceptor vesicles. The anthrylvinyl and perylenoyl energy transfer pair offers advantages over frequently used energy transfer pairs such as NBD and rhodamine. The anthrylvinyl emission overlaps effectively the perylenoyl excitation spectrum and the fluorescence parameters of the anthrylvinyl fluorophore are nearly independent of the medium polarity. The nonpolar fluorophores are localized in the hydrophobic region of the bilayer thus producing minimal disturbance of the bilayer polar region. Our results indicate that this method is suitable for assay of lipid transfer proteins including mechanistic studies of transfer protein function.  (+info)

  • The structure of CD1b complexed with glucose monomycolate, reported in this study, confirms this hypothesis and illustrates how the distinctive substituents of intracellular bacterial glycolipids can be accommodated. (ox.ac.uk)
  • α-Gal glycolipids capable of converting tumors into endogenous vaccines, have α-gal epitopes (Galα1-3Galβ1-4GlcNAc-R) and are extracted from rabbit RBC membranes. (elsevier.com)
  • A structure of CD1b complexed with relatively short acyl chain glycolipids plus detergent suggested how an interlinked network of channels within the Ag-binding groove could accommodate acyl chain lengths of up to 80 carbons. (ox.ac.uk)
  • A comparison of the glycolipids found in different strains of ascites tumour cells in mice. (jax.org)
  • Insertion of α-gal glycolipids and subsequent binding of anti-Gal are further demonstrated with human melanoma cells, suggesting that intratumoral injection of α-gal glycolipids is likely to elicit a protective immune response against micrometastases also in cancer patients. (elsevier.com)
  • The crystal structure of human CD1b with a bound bacterial glycolipid. (ox.ac.uk)
  • The human MHC class I-like molecule CD1b is distinctive among CD1 alleles in that it is capable of presenting a set of glycolipid species that show a very broad range of variation in the lengths of their acyl chains. (ox.ac.uk)
  • The present study demonstrates the ability of α-gal glycolipids treatment to prevent development of metastases at distant sites and to protect against tumor challenge in the treated mice. (elsevier.com)
  • Glycolipids are lipids with a carbohydrate attached by a glycosidic bond. (wikipedia.org)
  • They can also remove glycans from glycolipids to turn them back into unmodified lipids. (wikipedia.org)
  • glycosphingolipids, however, constitute a special class of glycolipids in that they incorporate into their structures a class of lipids called ceramides, which comprise the lipid sphingosine and a fatty acid tail. (google.com.au)
  • The structural diversity of glycolipids is exceptional, as different types of lipids are glycosylated in almost every forms of life like animals, plants, and bacteria. (omicsonline.org)
  • In the Carbosurf project, the hurdles that hamper the full exploitation of two specialty biochemical classes with high market interest were addressed, namely glycolipid biosurfactants (new types of sophorolipids and sophorosides, rhamnolipids, mannosylerythritol lipids (MELs) and xylolipids) and specialty carbohydrates (sialyllactose and LactoNtetraoses). (europa.eu)
  • For the fourth type of glycolipid (mannosylerythritol lipids (MELs)), smaller scale fermentations were performed to investigate the purification and produce product for application tests. (europa.eu)
  • 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. (asm.org)
  • Mannosylerythritol Lipids (MEL's) are glycolipid biosurfactants that contain 4-O-β-D-mannopyranosyl-meso-erythritol as a hydrophilic moiety and fatty acids as a hydrophobic moiety. (thescipub.com)
  • Glycolipids are major components of the plasma membrane, interacting with themselves, other lipids, and proteins to form an array of heterogeneous domains with diverse biological properties. (ox.ac.uk)
  • These short chains of sugar molecules are usually found associated with another molecule including proteins (glycoproteins) and lipids (glycolipids). (abpischools.org.uk)
  • Marine glycolipids, as well as those from terrestrial organisms, are amphiphylic compounds which are currently divided into two main groups: glycoglycerolipids (GGLs) and glycosphingolipids (GSLs). (springer.com)
  • The four main human blood types (A, B, AB, O) are determined by the oligosaccharide attached to a specific glycolipid on the surface of red blood cells, which acts as an antigen. (wikipedia.org)
  • Systematic analysis of the composition of the heterocyst specific glycolipid fraction, labelled from either sodium [l-acetate or Na H 14CO3 in the filamentous heterocystous Cyanobacterium Anabaena cylindrica, showed that the glycose ester fraction normally contained 10-16% of the heterocyst glycolipid radioactivity, while the glycosidic fraction contained the remainder of the heterocyst glycolipid radioactivity. (bl.uk)
  • Furthermore, an enzyme-linked immunosorbent assay (ELISA) based on type-specific glycolipid antigens and infected swine sera was used to diagnose the serological types of the MAI complex isolates. (asm.org)
  • We have characterized the major glycolipid constituents of the mouse peritoneal macrophage, and have demonstrated that alterations in the amount and in the accessibility of specific glycolipid species to galactose oxidase/NaB3H4 labeling, an indicator of glycolipid surface exposure, occur in response to inflammation and as a consequence of activation to a tumoricidal state. (umassmed.edu)
  • Selectins, a class of lectins found on the surface of leukocytes and endothelial cells bind to the carbohydrates attached to glycolipids to initiate the immune response. (wikipedia.org)
  • A set of microbial strains efficiently producing (new types) of glycolipids (new-to-nature sophorolipids and sophorosides, rhamnolipids and xylolipids) and producing specialty carbohydrates were thus created. (europa.eu)
  • Carbohydrates covalently attached to glycolipids are not the exception. (frontiersin.org)
  • Carbohydrates on glycolipids are the most exposed structures on the extracellular surface of cells and are flexible with numerous binding sites which make them optimal for cell signaling. (libretexts.org)
  • Using this protocol, we have established that the binding of bacterial toxins, lectins, and antibodies can each be attenuated, enhanced, or unaffected in the presence of glycolipid complexes, as compared with individual, isolated glycolipids. (ox.ac.uk)
  • The main objective of this project is to develop a novel immunotherapy for gliomas, in which glycolipid antigens are analyzed and quantified systematically and a set of appropriate antibodies would be selected according to the antigenic profile of an individual glioma. (nii.ac.jp)
  • A specific family of glycolipids, the globoseries, was shown to act as receptors on human uroepithelial cells and erythrocytes for the majority of uropathogenic Escherichia coli strains attaching to or hemagglutinating those cells. (asm.org)
  • A major part of the structural diversity in this family of glycolipids involves increasing degrees of acetylation and differing positions of acetylation on a common pachymoside glycolipid template. (ubc.ca)
  • M. bovis also contains other minor seroreactive phenolic glycolipids, one of which is a deacylated form of mycoside B and another of which contains an α-L-rhamnopyranosyl unit rather than 2-O-methyl-α-L-rhamnopyranose. (elsevier.com)
  • Novel, optically active azido alcohols are synthesized from N-haloacetyl oxazolidinone and are coupled with protected, activated carbohydrate residues in stereoselective glycosidic fashion to provide glycolipids in substantially pure stereochemical form. (google.com.au)
  • The structure of the major glycolipid produced by the strain was analyzed by 1 H and 13 C nuclear magnetic resonance and was found to be similar to those of well known MEL-A, -B and -C respectively. (thescipub.com)
  • It was revealed that the total glycolipids were expressed nearly twice during mitosis, and nLc4Cer was significantly enhanced during that phase. (nii.ac.jp)
  • approximately 5% of the total glycolipids in the brain are found in the soluble fraction. (libretexts.org)
  • approximately 70% of total glycolipids are found in these rafts which form hydrophobic interactions . (libretexts.org)
  • Antigens which are not present in an individual's blood will cause antibodies to be produced, which will bind to the foreign glycolipids. (wikipedia.org)
  • Ac2SGL, one of the glycolipids in the cell enveloppe of M. tuberculosis , stimulates the production of antibodies and is considered as a candidate for a tuberculosis vaccine. (rug.nl)
  • I. Antigenicity of the glycolipids and the production of specific antibodies in rabbits. (rupress.org)
  • Amino acids that allow for side chain functionalization with glycosyl moieties, such as serine and aspartic acid, have been popular choices as the starting point for the preparation of glycolipid analogues [ 8 , 9 ]. (mdpi.com)
  • Despite the potential interest for drugs mimicking glycolipid structure and function, the physicochemical properties of authentic glycolipids suggested that it might be difficult to obtain synthetic glycolipid analogues able to neutralise those pathogens before they could reach the cell surface. (eurekaselect.com)
  • The in vivo dynamics of the NKT cell population in response to glycolipid activation remain poorly understood. (jci.org)
  • The immunosuppressive function of glycolipids in vivo is thought to be related to direct inhibitory effects by means of the modulation of T lymphocyte signal transduction and effector cell differentiation or development ( 19 , 20 ). (pnas.org)
  • Because the cytokine response profile is governed by the structure of the glycolipid, we sought a method for labeling various glycolipids to study their in vivo behavior. (ox.ac.uk)
  • Quantitative and qualitative differences in the in vivo response of NKT cells to distinct alpha- and beta-anomeric glycolipids. (ox.ac.uk)
  • These findings indicate that NKT cells can fine-tune their immune responses to distinct glycolipid Ags in vivo, a property that may be exploited for the development of effective and safe NKT cell-based immunotherapies. (ox.ac.uk)
  • This study investigated the effects of Ka on glycolipid metabolism and explored the underlying mechanisms of action in vivo and vitro. (researchsquare.com)
  • We hypothesized that the glycolipid(s) shed by L5178Y-R inhibited antigen presentation by CD1d1. (pnas.org)
  • These results suggest that one means by which certain tumor cells can evade the host's innate antitumor immune response is by shedding glycolipids that inhibit CD1-mediated antigen presentation to NKT cells. (pnas.org)
  • Pili and lipopolysaccharide of Pseudomonas aeruginosa bind to the glycolipid asialo GM1. (asm.org)
  • 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. (asm.org)
  • The glycolipid composition of the urogenital epithelium and kidney tissue and the ability of uropathogenic E. coli to bind to these glycolipids may be a determinant in host-parasite interaction leading to urinary tract infection. (asm.org)
  • Applications where the tools discussed in this paper are particularly useful include, among others, the preparation of structures for glycolipids, nanocellulose, and glycans linked to glycoproteins. (helsinki.fi)
  • The nature of the building blocks should allow for a modular approach which could lead to the facile preparation of a small collection of glycolipids of different fatty acids chain lengths, such as 1 - 4 , shown in Figure 1 b. (mdpi.com)
  • Similar intratumoral injection of alpha-gal glycolipids in humans is likely to induce the destruction of treated lesions and elicit a protective immune response against micrometastases. (umassmed.edu)
  • For example, glycolipids have an important role in the immune response. (wikipedia.org)
  • Fractionation of the fatty alcohols from the heterocyst glycolipid glycoside fraction gave four labelled components. (bl.uk)
  • Whereas trichloroacetic acid, sodium fluoride, and dichlorallyl-di-isopropyl thiocarbamate which each inhibit fatty acid elongation in higher plants, did not inhibit incorporation of sodium [1-14C] acetate into the very long chain components of the heterocyst glycolipid fraction in whole cells of A.cylindrica. (bl.uk)
  • Sodium arsenite, which inhibits elongation of palmitic acid to stearic acid in higher plants caused a specific inhibition of incorporation of label into the major very long chain component of the heterocyst glycolipid, which was accompanied by an accumulation of radioactivity in C16 fatty acids specifically in the monogalactosyl diglyceride fraction. (bl.uk)
  • The basic structure of a glycolipid consists of a mono- or oligosaccharide group attached to a sphingolipid or a glycerol group (can be acetylated or alkylated) with one or two fatty acids. (libretexts.org)
  • An example of how glycolipids function within the body is the interaction between leukocytes and endothelial cells during inflammation. (wikipedia.org)
  • Intratumoral injection of alpha-gal glycolipids results in local inflammation mediated by anti-Gal binding to the multiple alpha-gal epitopes and activation of complement. (umassmed.edu)
  • These observations suggest that both a chemical and spatial reorganization of surface glycolipids occurs in response to inflammation and tumoricidal activation. (umassmed.edu)
  • This study investigated which adhesins of Pseudomonas aeruginosa interact with the glycolipid asialo GM1, using solid-phase binding and thin-layer chromatography assays. (asm.org)