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PubMed1986

Novel blood group H glycolipid antigens exclusively expressed in blood group A and AB erythrocytes (type 3 chain H). I. Isolation and chemical characterization.

A series of blood group H antigens reacting with monoclonal antibody MBrl has been found in human blood group A and AB erythrocytes, but not in O or B erythrocytes. These H antigens are clearly different from the globo-H structure (Fuc alpha 1----2Gal beta 1----3GalNAc beta 1----3Gal alpha 1----4Gal beta 1----4Glc beta 1----1Cer), which was previously isolated from O erythrocytes and is also reactive with the MBrl antibody. The new series of H antigens associated with blood group A has been characterized as having TLC mobilities which approximately coincide with those of H2, H3, and H4 glycolipids. One of these A-associated H antigens, having a similar TLC mobility as the H2 glycolipid, was isolated from A erythrocytes and was characterized by 1H NMR spectroscopy, methylation analysis, and enzymatic degradation as having the structure shown below: (formula, see text). The structure represents a precursor of the repetitive A epitope attached to type 2 chain, previously called type 3 chain A (Clausen, H., Levery, S. B., Nudelman, E., Tsuchiya, S., and Hakomori, S. (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 1199-1203). This A-associated H structure is hereby called type 3 chain H.

ABO Blood-Group System↗
PubMed1985

Pyruvylated glycolipids from Mycobacterium smegmatis. Nature and location of the lipid components.

The dipyruvylated glycolipid from Mycobacterium smegmatis (Saadat, S., and Ballou, C.E. (1983) J. Biol. Chem. 258, 1813-1818) has been shown to have the following structure in which FA1 is tetra- or hexadecanoic acid and FA2 is 2,4-dimethyl-2-eicosenoic acid. (formula; see text) The fast atom bombardment mass spectrum showed two major ions [M - H]- at m/z 1511 and 1539 (Mr 1512 and 1540) in a ratio of 1.4:1, suggesting that the glycolipid was a mixture of homologs that differed in fatty acid composition by 2 methylene groups. Analysis revealed C14, C16, and C22 fatty acids in ratios of 0.6:0.4:1.0, indicating that 60% of the molecules contained a C14 and C22 fatty acid whereas 40% contained a C16 and C22 fatty acid. The fragmentation pattern showed that a single glucose unit along with the smaller fatty acid could be lost to yield a tetrasaccharide with attached C22 fatty acid, and a second fragmentation yielded a trisaccharide containing 2 pyruvic acids but without attached fatty acid. The C14 and C16 fatty acids were identified as myristic and palmitic acid, whereas the C22 fatty acid was 2,4-dimethyl-2-eicosenoic acid. Precise localization of the fatty acids came from periodate oxidation and methylation analysis.

Fatty Acids↗
PubMed1985

Enzymatic basis for the accumulation of glycolipids with X and dimeric X determinants in human lung cancer cells (NCI-H69).

Many human carcinomas accumulate a large quantity of glycolipids having X (Gal beta 1----4[Fuc alpha 1----3] GlcNAc) as well as di- or trimeric X determinant (Gal beta 1----4 [Fuc alpha 1----3] GlcNAc beta 1----3Gal beta 1----4 [Fuc alpha 1----3]GlcNAc beta 1----3Gal) (e.g. Hakomori, S., Nudelman, E., Levery, S. B., and Kannagi, R. (1984) J. Biol. Chem. 259, 4672-4680). The enzymatic basis of this phenomenon has been investigated with human small cell lung carcinoma NCI-H69 cells, in which a series of these structures has been found to accumulate. An alpha 1----3 fucosyltransferase solubilized from the membrane fraction with Triton X-100 catalyzed not only the transfer of a fucosyl residue from GDP-fucose to the penultimate GlcNAc residue of lactoneotetraosylceramide (nLc4) and lactonorhexaosylceramide (nLc6), but also to the internal GlcNAc residue (III-GlcNAc) of y2 glycolipid (V3FucnLc6) and that of sialosyl2----6lactonorhexaosylceramide (VI6NeuAcnLc6). No transfer of fucose to the internal GlcNAc (III-GlcNAc) of lactonorhexaosylceramide occurred, unless the above substitutions (V3Fuc or VI6NeuAc) were present. Fucosylation at V-GlcNAc and III-GlcNAc of nLc6 could be catalyzed by the same enzyme, based on the following observations: (i) fucosylation at both III- and V-GlcNAc was competitively inhibited by V3FucnLc6 and III3V3Fuc2nLc6; (ii) the same conditions (pH, bivalent cation, detergent) were optimal for fucosylation at both III- and V-GlcNAc; (iii) the Km values of the enzyme for nLc4, nLc6, and V3FucnLc6 were approximately the same; and (iv) the activity of the enzyme catalyzing fucosylation at both III- and V-GlcNAc was adsorbed on GDP-hexanolamine-Sepharose and was not inhibited by N-ethylmaleimide. The enzyme preferentially transferred fucose to the penultimate VGlcNAc, followed by transfer to the internal III-GlcNAc of nLc6. Thus, the pathway for synthesis of dimeric X proceeds as follows: nLc6----V3FucnLc6----III3V3Fuc2nLc6. No mechanism was found to operate for chain elongation of the X hapten structure through addition of GlcNAc residues to the terminal Gal of the X hapten.

Carbohydrate Conformation↗
PubMed1977

High performance thin layer chromatography of neutral and acidic glycolipids: application to the chemical diagnosis of lipid storage diseases.

A new technique was utilized for the separation of neutral and acidic glycolipids using an equipment named U-Chamber System. This technique was employed for the chemical diagnosis of inherited inborn errors diseases in which complex glycolipids are involved. Results in the identification of storage products in Tay-Sachs' disease, GM1 gangliosidosis and Fabry's disease are presented.

Chromatography, High Pressure Liquid↗
PubMed1973

Structure determination of the glycolipid sulfate from the extreme halophile Halobacterium cutirubrum.

A sulfur-containing glycolipid, accounting for ca. 25% of the total polar lipids, has been isolated from the extreme halophile Halobacterium cutirubrum. The ammonium salt of the lipid was found to have the molecular formula C(61)H(117)O(21)S.NH(4), and on strong acid hydrolysis it yielded 2,3-di-O-phytanyl-sn-glycerol, glucose, mannose, galactose, and sulfate in equimolar proportions. Infrared and NMR spectra indicated the presence of a secondary sulfate group. Solvolysis of the lipid in 0.004 m HCl in tetrahydrofuran resulted in rapid release of inorganic sulfate and formation of galactosyl-mannosyl-glucosyl diphytanyl glycerol ether. With higher acid concentration (0.25 m methanolic HCl), stepwise hydrolysis of monosaccharide units occurred, giving mannosyl-glucosyl glycerol diphytanyl ether and monoglucosyl glycerol diphytanyl ether. The position of attachment of the sugars and of the sulfate group was determined by methylation of the free acid form of the glycolipid sulfate, followed by acid hydrolysis and gas-liquid chromatographic analysis of the partially methylated sugars as the alditol acetates. The configuration of the glycosidic linkages was established both by optical rotation measurements and by specific enzymatic hydrolysis. The results obtained established the structure as 2,3-di-O-phytanyl-1-O-[beta-d-galactopyranosyl-3'-sulfate-(1' -->6')-O-alpha-d-mannopyranosyl-(1' --> 2')-O-alpha-d-glucopyranosyl]-sn-glycerol.

Chromatography↗
PubMed1979

Lipids in the Harder's gland of certain rodents. III: Glycolipids.

Following the study of total lipid and phospholipid contents of Harderian gland, we carried out analysis of glycolipid fractions. The data showed that most of the pigment is bound to mono-hexose ceramides, while only a minor fraction of it is bound to ceramides and/or to phospholipids. Histochemical studies confirmed the lipid and glycolipid nature of the Harder's gland secretion. The presence of mono-hexose ceramides linked to the characteristic fluorescent porphyrin was shown.

Animals↗
PubMed1970

Glycolipid abnormalities in a myoclonic variant of late infantile amaurotic idiocy.

Glycolipids were isolated from the brain of a patient with a myoclonic variant of late infantile amaurotic idiocy. There was an abnormal glycolipid pattern in gray and white matter. The observed high concentration of gangliosides was due to a uniform accumulation of all four major gangliosides and was not limited to one species such as ganglioside A(1), as in Tay-Sachs disease, or ganglioside A(2), as in gangliosidosis-Gm1. Two additional stored substances were identified as ceramide lactoside and ceramide tetrahexoside. Partial and total hydrolysis of these ceramide hexosides revealed that their ceramide moiety is identical with the ceramide portion of gangliosides. The sequence of hexoses in the carbohydrate chain of the ceramide dihexoside and ceramide tetrahexoside further suggests a metabolic and chemical relation to gangliosides. Some implications of these findings for the theories of the metabolic defects in gangliosidoses are discussed.

Brain↗
PubMed1968

Fatty acid composition of brain glycolipids in Alzheimer's disease, senile dementia, and cerebrocortical atrophy.

Quantitative fatty acid compositions are reported for human cerebral gray matter glycolipids (gangliosides, cerebrosides, and cerebroside sulfates) in Alzheimer's disease (presenile dementia) and related disorders of the central nervous system. Although the fatty acid compositions were generally similar to those of the controls, some significant differences were noted in Alzheimer's disease which were not found in the single samples of senile dementia and of senile cerebrocortical atrophy. In the ganglioside fatty acids, the percentage of palmitic acid was higher in all three cases of Alzheimer's disease than in the controls. In cerebrosides, the proportion of 2-hydroxy to non-hydroxy acids was slightly lower in Alzheimer's disease than in controls and the relative proportions of 2-hydroxystearic acid and 2-hydroxytricosenoic acid were slightly higher. In cerebroside sulfates, monounsaturated 2-hydroxy acids were lower in two of the samples with Alzheimer's disease. The results indicate possible effects of the degenerative changes in this disease on glycolipid metabolism.

Aged↗
PubMed1978

Human antithrombin III. Carbohydrate components and associated glycolipid.

Human antithrombin III was found to contain covalently linked N-acetylglucosamine, mannose, galactose, and sialic acid in a molar ratio of approximately 1:1:0.6:1. Sialic acid was released upon treatment with neuraminidase. The modified glycoprotein retained the capability to inhibit thrombin and to bind with heparin. Antithrombin III isolated by different procedures was also found to contain glucose in an approximately equimolar ratio with N-acetylglucosamine. Th" glucose-containing component was extractable with lipid solvents and shown to be beta-glucosylceramide. This glycolipid is tightly complexed with antithrombin III and could not be separated by fractional precipitations or ion exchange gels. Although it remains to be established whether the inhibitory actions of antithrombin III are affected by glucosylceramide, the relative amounts which are bound suggest that antithrombin III may be a significant carrier of the glycolipid.

Antithrombins↗
PubMed1984

Hybrid type glycolipids (lacto-ganglio series) with a novel branched structure. Their presence in undifferentiated murine leukemia cells and their dependence on differentiation.

The structures of these glycolipids are hybrids of the lacto and ganglio series, which are characterized by the presence of GlcNAc beta 1----3 and GalNAc beta 1----4 linked to the Gal residue of Gal beta 1----4Glc beta 1----1Cer. This new hybrid series can be designated as "lacto-ganglio series." These glycolipids are present in undifferentiated murine leukemia cells. Their concentration declines with differentiation and they are virtually absent in differentiated M1+ cells, suggesting that lacto-ganglio structures could be markers of undifferentiated, malignant myeloid cells.

Animals↗
PubMed1980

Urinary glycolipids of YC8 lymphoma bearing mice: effectors of glycosylation process.

Glycolipids from YC8 lymphoma bearing mice urines have peen obtained by the method of Folch and fractionated on silicic column and on silica gel plates. One fraction, among the five obtained, may be used by sera galactosyltransferase as an acceptor for galactose, to form a new glycolipid compound. Furthermore this fraction has shown an inhibitory effect on phosphatase activity, in agreement with hypothesis which relates relates glycosyltransferase and phosphatase activities during tumorous process.

Animals↗
PubMed1984

Effect of glycolipids contained in liposomes on the incorporation of beta-galactosidase into specific organs.

A series of glycolipids were examined to find a system capable of targeting liposomes into specific organs of rats. Sulfatide was found to be the best among the components of liposomes examined for delivering the entrapped enzyme, beta-galactosidase from Aspergillus oryzae, into the brain and liver; gangliosides, for the spleen; and sphingomyelin, for the lung. To introduce the enzyme into the liver, galactocerebroside was far better than glucocerebroside. These data suggest that the sugar residues of glycolipids function to target the liposomes into specific organs.

Animals↗
PubMedDate not supplied

[Neutral glycolipids of blood in normal state and in hypertension].

Neutral glycolipids of blood constituted four main fractions both in healthy persons and in patients with hypertension. An increase in di- and trihexosylceramides in blood plasma and in monohexosylceramides from erythrocytes occurred simultaneously with elevation of total blood glycolipids in hypertension.

Erythrocytes↗
PubMed1983

Human platelet cytoskeletons: specific content of glycolipids and phospholipids.

The lipid composition of platelet cytoskeletons was analyzed. Triton X-100 (0.5%) was used to prepare cytoskeletons from thrombin-treated platelets. The lipid/protein ratio of platelet cytoskeletons was 0.260 and the phospholipid/protein ratio was 0.177, which were comparable to the ratios present in platelets. However, there was a selective enrichment of platelet lipids in platelet cytoskeletons. Only 2 of the 5 major platelet phospholipids were detected. About 14% platelet sphingomyelin and 2% platelet phosphatidylcholine were present in platelet cytoskeletons. Only 1 of the 4 platelet neutral glycolipids, trihexosyl ceramide, was detected and was about 7% of that in intact platelets. Two percent of platelet hematoside, the predominant ganglioside in platelets, was found in cytoskeletons. Six percent of platelet cholesterol was present in platelet cytoskeletons, while no other neutral lipid could be detected. The study demonstrates that the lipid/protein ratio of platelet cytoskeletons is similar to that in platelets, but the composition of cytoskeleton lipids is specific and distinctly different from that in platelets. The selective glycolipid and phospholipid composition of cytoskeletons may be important for cytoskeleton and platelet function.

Blood Platelets↗
PubMed1982

Cytoskeleton-associated glycolipid (CAG) and its cell biological implication.

Previous immunohistochemical studies showed that galactocerebroside (GC) exists not only in the plasma membrane but also in a colchicine-sensitive microtubule-like cytoskeletal structure in various cultured cells and tissues. This distribution of galactocerebroside may also be true of other glycosphingolipids and, therefore, we called these glycolipids cytoskeleton-associated glycolipid (CAG). This article gives further precise morphological information on the location of CAG and discusses its cell biological and biochemical implications, considering CAG as a fundamental component of the cytoskeleton.

Animals↗
PubMed1983

Pyruvylated glycolipids from Mycobacterium smegmatis. Structures of two oligosaccharide components.

A crude glycolipid fraction was isolated from Mycobacterium smegmatis ATCC 356 by ethanolic extraction and silica gel chromatography. After deacylation of the glycolipid fraction, a dipyruvylated pentasaccharide (acidic oligosaccharide A) and a monopyruvylated tetrasaccharide (acidic oligosaccharide B1) were purified by ion exchange and gel filtration chromatography. Methylation analysis, proton nuclear magnetic resonance, mass spectrometry, and periodate oxidation suggested that oligosaccharide A was 4,6-(1-carboxyethylidene)-3-O-methyl-beta-D Glcp-(1-3)-4,6-(1-carboxyethylidene)-beta-D-Glcp-(1-4)-beta-D-Glcp-(1-6)-alpha- D Glcp-(1-1)-alpha-D-Glcp and that oligosaccharide B1 was 4,6-(1-carboxyethylidene)-beta-D-Glcp-(1-4)-beta-D-Glcp-(1-6)-alpha-D-Glcp-(1-1 ) -alpha-D-Glcp. Both compounds contain a trehalose unit as a part of the oligosaccharide structure, and B1 appears to be a biosynthetic precursor of A because the two differ only in a pyruvylated 3-O-methylglucose unit. A third component, acidic oligosaccharide B2, differs from oligosaccharide A only in lacking 1 of the 2 pyruvate residues.

Carbohydrate Conformation↗
PubMed1981

Glycolipids of murine lymphocyte subpopulations: a defect in the levels of sialidase-sensitive sialosylated asialo GM1 in beige mouse lymphocytes.

Neutral glycosphingolipids as well as some of the sialic acid containing glycolipids, or gangliosides, were quantitated from thymocytes and splenic T lymphocyte preparations from normal and natural killer-deficient mice of various ages. Previously, asialo GM1 was considered the product of acid hydrolysis of the ganglioside GM1. However, in the murine lymphoid system asialo GM1 is a normally occurring glycolipid that appears to be one of the intermediates in the biosynthesis between lactosylceramide and some recently described, terminally sialosylated gangliosides (for structures see Table I). Asialo GM1, which is a putative marker for murine natural killer cells, is unaltered in thymocytes but is found at reduced levels in 5- to 15-wk-old beige mouse splenic T cell preparations. A sialosylated derivative of asialo GM1, which is sialidase sensitive, is increased in postnatal splenic lymphocytes but then falls to below normal levels in 5- to 15-wk-old beige mice. The concentration of this ganglioside is also altered in the same manner in the thymus. Analysis of the total gangliosides of beige thymus and spleen indicates that there are several possible deletions, but it still not known whether these deletions are related to the natural killer dysfunction in these mice. These studies show that there is a defect in the synthesis or degradation of several related glycosphingolipids in beige lymphocytes, at least 1 of which contains sialic acid, but whose structure remains unknown.

Animals↗
PubMed1982

[Regulation of the superprecipitation of an actomyosin-like protein from the brain by glycolipids].

The optimal conditions (ionic strength, pH, Mg2+ and ATP concentrations) for nephelometric determination of the superprecipitation reaction of the actomyosin-like protein (AMLP) from ox brain cortex are described. At low ionic strength (0.1 M KCl, 200 micrograms of protein, pH 6.8, 37 degrees) MgATP (1 mM) first causes a fast (1--2 min) dissociation of AMLP with a decrease in the optical density (A620) at 620 nm and then a slow (15--20 min) true superprecipitation associated with a substantial rise of A620. EGTA (0.1 mM) moderately, i. e. by 20%, inhibits the reaction. The effects of glycolipids (total gangliosides and cerebrosides from ox brain) and phosphatidyl choline from chicken egg yolk on aggregation (without Mg-ATP), dissociation and superprecipitation of AMLP were examined. It was found that gangliosides (40 micrograms) and cerebrosides (2--80 micrograms) cause aggregation of AMLP; phosphatidylcholine (4--160 micrograms) has no effect on protein aggregation. Gangliosides within the concentration range of 0.8--4.0 micrograms do not cause AMLP aggregation but strongly inhibit superprecipitation of the protein, whereas phosphatidylcholine (40--80 micrograms) has practically no effect on the reaction intensity. A hypothesis on regulation by glycolipids on contractile proteins from brain presynaptic membranes under varying rest--excitation conditions is postulated.

Actomyosin↗