Comparative study of glycolipid compositions of plasma membranes among two types of rat ascites hepatoma and normal rat liver.

Glycolipid composition of purified plasma membranes from rat ascites hepatomas, two island-forming cell-lines and two cell-lines of the free-type, and normal rat liver were compared. Ceramide monohexoside (CMH), ceramide dihexoside (CDH), and hematoside (GM3) were found in normal rat liver cell membranes. The island-type hepatomas contained ceramide trihexoside (CTh) and globoside besides CMH, CDH, and GM3. The free-type of hepatomas were characterized by the presence of asialo-type gangliosides but not GM3. The free-type of hepatomas were characterized by the presence of asialo-type gangliosides but not GM3. Blood group H active fucolipid was a major glycolipid in the free-type of ascites hepatoma cell (AH 7974 F). The increase of glycolipid content in cell membranes seemed to be accompanied with a decrease of cell adhesiveness.     

Glycosphingolipids in murine lymphocytes from thymus and spontaneous and X-ray induced thymomas

Lymphocytes from spontaneous thymoma in AKR mice and from X-ray induced thymoma in C57B1/6 mice showed elevated levels (by 50% and 100%, respectively) of lipid-bound sialic acid as compared with lymphocytes from normal thymuses used as controls. Some ganglioside fractions in thymomas were elevated 4-6-fold over those in normal thymuses while other fractions decreased or disappeared. Neutral glycosphingolipid (NGSL) content in lymphocytes from thymomas was also changed. Thin-layer chromatography of NGSLs showed that the fractions migrating as ceramide monohexoside (CMH), dihexoside (CDH) and below globoside standards were increased, respectively, 2-3-fold, 3-6-fold and 2-fold in both types of thymomas. Methylation and gas-liquid chromatography analysis confirmed the presence of CMH, CDH and globoside in NGSLs isolated from X-ray induced thymoma.     

Two strains of the Madin-Darby canine kidney (MDCK) cell line have distinct glycosphingolipid compositions.

The glycosphingolipids (GSLs) of two sublines of Madin-Darby canine kidney (MDCK) cells, an epithelial cell line, were characterized by t.l.c., antibody overlay and mass spectrometry. The major characteristic which distinguishes the two MDCK cell strains is their trans-epithelial electrical resistance which is typically of the order of 3000 ohm.cm2 for strain I and 100 ohm.cm2 for strain II cells. Strain I and II cells were equally rich in glycolipids, the cellular GSL/phospholipid ratio being 0.04. However, while the phospholipid patterns were identical, the GSLs showed striking differences, and each cell strain expressed appreciable amounts of GSLs that were not found in the other strain. Both cell types possessed neutral GSLs with one, two or three carbohydrate moieties. The monoglycosylceramide accounted for 50% of the total GSLs in each strain. However, while in strain I cells over 90% of this monoglycosylceramide was monoglucosylceramide, in strain II cells over 90% consisted of monogalactosylceramide. In addition, MDCK strain II cells selectively expressed GSLs belonging to the globo series (26% of its neutral GSLs), including globoside and Forssman antigen, a globoside derivative. MDCK strain I cells, on the other hand, expressed another series of GSLs with 4-7 carbohydrate moieties characterized by the common sequence Hex-HexNAc-Hex-Hex-Cer. The presence of two fucosylated GSLs in these series was established. Both MDCK strain I and II cells contained negatively charged GSLs, the major component of which was the ganglioside GM3. MDCK strain II cells in addition expressed sulfatide, the sulfated derivative of galactosylceramide.(ABSTRACT TRUNCATED AT 250 WORDS)     

Glycosphingolipid patterns of peripheral blood lymphocytes, monocytes, and granulocytes are cell specific

We analyzed the amounts and types of glycosphingolipids (GSLs) from peripheral blood lymphocytes, monocytes, and granulocytes isolated by counter-current elutriation. The three cell types contained different amounts of neutral and acidic GSLs. The highest amount of neutral GSLs (109 micrograms/10(8) cells) was found in granulocytes, with considerably less found in monocytes (11 micrograms/10(8) cells) and lymphocytes (4 micrograms/10(8) cells). The neutral GSLs were composed of four types of lipids, GL1 through GL4 (mono-, di-, tri-, and tetraosylceramide). The highest percentage of GL1 was detected in lymphocytes and the lowest percentage in granulocytes, with the reverse order observed for GL2. GL3 and GL4, which were minor components of the neutral GSLs, were highly cell specific, with lymphocytes containing GL3 and GL4 of the globo series, granulocytes containing GL3 and GL4 of the lacto or neolacto series, and monocytes containing GL3 and GL4 of both types. The acidic GSL, sialosyl hexaosylceramide (lacto-series), was abundant in granulocytes but not in monocytes or lymphocytes. Another ganglioside, GM3, although present in all three cell types, was most abundant in monocytes and lymphocytes, whereas sialosyl paragloboside was higher in granulocytes than in lymphocytes and monocytes. These results indicate that peripheral blood lymphocytes, monocytes, and granulocytes have distinct "GSL fingerprints."     

Identification of the neutral glycosphingolipids of murine mast cells: expression of Forssman glycolipid by the serosal but not the bone marrow-derived subclass

The expression of neutral glycosphingolipids by mouse T cell-dependent, bone marrow-derived mast cells (BMMC) obtained in vitro was determined by chromatographic and immunochemical criteria. Neutral glycosphingolipids were isolated from BMMC by extraction of 3 to 5 X 10(8) cells in chloroform/methanol (1/1, v/v) and chromatography on DEAE-Sephadex, and were analyzed by thin layer chromatography with orcinol staining. The predominant neutral glycosphingolipids of BMMC were glucosylceramide (CMH), lactosylceramide (CDH), globotriosylceramide (CTH), globotetraosylceramide (globoside), and a molecule migrating slightly faster than gangliotetraosylceramide (asialo GM1) and slower than globopentaosylceramide (Forssman glycolipid). The profiles on thin layer chromatograms of the neutral glycosphingolipids were the same for BMMC derived from BALB/c, C57BL/6, WBBF1-W/Wv, and WBBF1-+/+ mice, and for cells differentiated in either WEHI-3 conditioned medium or concanavalin A-splenocyte conditioned medium. High performance liquid chromatography of benzoylated neutral glycosphingolipids of BMMC on a Zipax column confirmed the identity of the four neutral glycosphingolipids identified by thin layer chromatography. The fifth major glycosphingolipid had an elution time greater than that of globotetraosylceramide and did not co-elute with any of the standards tested. Direct biochemical analyses of the neutral glycosphingolipids of mouse serosal mast cells (SMC) were not feasible because only 2 X 10(6) SMC could be isolated per 100 mice. However, mouse SMC bound a rat monoclonal anti-globopentaosylceramide antibody (M1/87.27.7) and rat monoclonal B1.1 antibody, as assessed by indirect immunofluorescence and flow cytometry, whereas mouse BMMC did not. The binding of B1.1 antibody to SMC could be blocked by the anti-globopentaosylceramide antibody, and the specificity of B1.1 antibody for globopentaosylceramide was confirmed immunochemically with the use of a solid phase radioimmunoassay. As estimated immunochemically, the amount of globopentaosylceramide in mouse SMC was 62 ng/10(6) cells, whereas BMMC contained less than 8 ng/10(6) cells. Thus, the expression of globopentaosylceramide is a characteristic of the mouse SMC that is lacking in the T cell-dependent BMMC.     

Subpopulations of B cells in germinal centers. III. HJ6, a monoclonal antibody, binds globoside and a subpopulation of germinal center B cells.

To identify surface Ag uniquely expressed on human germinal center B cells, we produced a mouse mAb, HJ6. When tonsillar lymphocytes were examined, HJ6 did not label T cells and labeled only about half of PNA+ B cells that were HK23-. HJ6 did not label mononuclear cells from peripheral blood, splenocytes, and any of 29 cell lines including 23 B cell lines. This binding pattern of HJ6 was very similar to that of a mAb named 5B5. It was shown previously that 5B5 bound a glycolipid named CTH (CD77) and its Ag was expressed on HK23- PNA+ tonsillar lymphocytes and Burkitt's lymphoma cell lines. Despite the similarity, HJ6 differed from 5B5: HJ6 did not stain Burkitt's lymphoma cell lines and stained PNA+ tonsillar lymphocytes in the presence of a large concentration of galactose. When its binding to isolated glycolipids was studied, HJ6 was found to bind globoside and Forssman Ag and not to other glycolipids including CTH. When its binding to neutral glycolipids extracted from tonsillar lymphocytes was studied, HJ6 bound only globoside; Forssman Ag was not detected in tonsillar lymphocytes. Taken together, we conclude that globoside is a B cell Ag expressed on a subpopulation of germinal center B cells.     

Global glycosphingolipid analysis in urine and plasma of female Fabry disease patients

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by deficiency of α-galactosidase-A, which results in accumulation of the glycosphingolipid (GSL) globotriaosylceramide (Gb₃). Gb₃ and globotriaosylsphingosine (lyso-Gb₃) levels in plasma and urine are used routinely for diagnosis and treatment monitoring. FD female patients are problematic to diagnose and to predict when to begin treatment. Further biomarkers are needed to detect pre-symptomatic females that will develop the chronic symptoms associated with FD. A LC-MS/MS glycosphingolipidomic assay was developed to measure lyso-Gb₃ and GSLs from the lysosomal GSL degradation pathway, including globoside (Gb₄), Gb₃, ceramide dihexosides (CDH) and ceramide monohexosides (CMH). We analysed plasma and urine from a cohort of Fabry patients, grouped according to clinical symptoms and independent of treatment status (asymptomatic females n = 18, symptomatic females n = 18, males n = 27 and control urines n = 16 and control plasmas n = 58).Multivariate and subsequent univariate analysis showed urine GSLs which had highest significance in identifying asymptomatic females were total levels of CDH, in particular the long chain isoforms C22:1,C22:0,C22:1-OH,C22:0-OH,C24:2,C24:0,C24:2-OH,C24:1-OH,C24:0-OH,C26:0 which likely represent Galabiosylceramide (Ga₂) and not lactosylceramide. These long chain Ga₂ isoforms were found to be 5-fold elevated and more statistically significant (p < 0.0001) than plasma lyso-Gb₃ (p < 0.01) in identifying asymptomatic Fabry female patients. Receiver operating characteristic curve analysis gave an area under the curve of 0.82 (p = 0.001) for lyso-Gb₃ and 0.88 (p = 0.0006) for long-chain CDH isoforms indicating the long chain CDH isoforms were as, if not more, a better biomarker for the identification of female FD patients.     

Stage-associated expression of ceramide structures in glycosphingolipids from the human trematode parasite Schistosoma mansoni

Glycosphingolipids of Schistosoma mansoni adults, cercariae and eggs comprise ceramide monohexosides (CMH) with glucose or galactose and ceramide dihexosides (CDH) with the schistosome-specific structure GalNAc(beta1-4)Glc(1-1)ceramide. Ceramide analysis revealed C18- and C20-phytosphingosines in egg CMH, C18-sphinganine as well as C18-, C19- and C20-phytosphingosines in cercarial CMH, and C18- and C20-phytosphingosines as well as C18-sphingosine and C18-sphinganine in adult CMH. For all three life cycle stages, the predominant fatty acid was C16h:0. As a characteristic feature, a range of saturated, unsaturated and hydroxylated long-chain fatty acids with 24-28 carbon atoms were additionally found in minor cercarial CMH species. The corresponding ceramides represented major constituents in cercarial CDH, while adult and egg CDH were dominated by ceramides with short fatty acid chains. The resultant ceramide patterns could be correlated with the differential expression of carbohydrate antigens on schistosomal glycolipids at various stages. A possible impact of ceramide structure on the biosynthesis of the carbohydrate moieties is discussed.     

The Chemical Structure of Glycolipids of Bovine Milk

Experiments were executed to elucidate the chemical structure of ceramide monohexoside (CMH) and ceramide dihexoside (CDH) isolated from cow’s milk, especially with regard to the nature of the sugar moiety of the molecules. The results have shown that the structure of CMH and CDH in bovine milk is β-glucosyl-(l→l)-N-acyl-sphingosine, namely ceramide glucoside, and β-galactosyl-(1→4)-β-glucosyl-(1→1)-N-acyl-sphingosine, namely ceramide lactoside, respectively.     

Release of carbohydrates from sphingoglycolipid by osmium-catalyzed periodate oxidation followed by treatment with mild alkali

The carbohydrate moiety of sphingoglycolipid, after preliminary acetylation, can be released by periodate oxidation catalyzed by a trace amount of osmium tetroxide, followed by alkaline treatment. Cerebroside, lactosyl ceramide, hematoside, globoside, and gangliosides were degraded to yield, respectively, galactose, lactose, sialyl lactose, a tetrasaccharide, and various oligosaccharides containing sialic acid. Oligosaccharides were separated by paper chromatography and paper electrophoresis. The procedure is useful for characterizing micromolar amounts of sphingoglycolipids.     

Glycosphingolipids from Magnaporthe grisea cells: expression of a ceramide dihexoside presenting phytosphingosine as the long-chain base

Magnaporthe grisea is a fungal pathogen that infects rice leaves and causes rice blast, a devastating crop disease. M. grisea produces active elicitors of the hypersensitive response in rice that were previously identified as ceramide monohexosides (CMHs). Using several chromatographic approaches, mass spectrometry, and nuclear magnetic resonance, we identified ceramide mono- and dihexosides (CDH) in purified lipid extracts from M. grisea cells. As described by other authors, CMH consists of a ceramide moiety containing 9-methyl-4,8-sphingadienine in amidic linkage to 2-hydroxyoctadecenoic or 2-hydroxyhexadecenoic acids and a carbohydrate segment consisting of one residue of glucose. CDHs, however, contain beta-galactose (1-->4)-linked to beta-glucose as sugar units and phytosphingosine as the long-chain base, bound to a C24 alpha-hydroxylated fatty acid. To our knowledge, this is the first report on the occurrence of CDH in a fungal species and illustrates the existence of an alternative path of ceramide glycosylation in fungal cells.     

Glycosphingolipids of human umbilical vein endothelial cells and smooth muscle cells

Glycosphingolipids (GSLs) represent an important class of immunogens and receptors. Although cell surface antigens and receptors of endothelial cells (ECs) have been the subject of extensive biochemical investigation, no information is available about their GSLs. We report here the characterization by chromatographic and immunological techniques of GSLs of cultured human umbilical vein ECs and, for comparison, umbilical vein smooth muscle cells (SMCs). The most abundant neutral GSLs of both cell types were lactosylceramide, Gb3, and Gb4, and both cells contained complex lacto and globo series compounds. Immunostaining revealed that ECs, but not SMCs, contained long chain GSLs bearing a type 2 blood group H determinant. ECs also contained more long chain GSLs bearing an unsubstituted terminal lactosamine structure than SMCs. Labeling with galactose oxidase/NaB3H4 demonstrated that neutral glycolipids that contained three or more sugars were accessible on the cell surface. The major gangliosides of both cell types were GM3 and IV3NeuAcnLc4. Immunostaining following neuraminidase treatment revealed that most of the long chain gangliosides in both types of cells contained a lacto core structure, and that ganglio series compounds were more abundant in SMCs than ECs. Gangliosides that contain a polyfucosyllactosamine core and a globo core were also present in both cell types. These results demonstrate that endothelial and smooth muscle cells contain a large diversity of GSL structures, and provide the basis for investigation of the role of these GSLs as cell surface antigens and receptors for blood components.     

Male germ cells require polyenoic sphingolipids with complex glycosylation for completion of meiosis: a link to ceramide synthase-3

Previously, it was found that a novel class of neutral fucosylated glycosphingolipids (GSLs) is required for male fertility. These lipids contain very long-chain (C26-C32) polyunsaturated (4-6 double bonds) fatty acid residues (VLC-PUFAs). To assess the role of these complex GSLs in spermatogenesis, we have now investigated with which of the testicular cell types these lipids are associated. During postnatal development, complex glycosylated and simple VLC-PUFA sphingolipids were first detectable at day 15, when the most advanced germ cells are pachytene spermatocytes. Their synthesis is most likely driven by ceramide synthase-3. This enzyme is encoded by the Cers3/Lass3 gene (longevity assurance genes), and out of six members of this gene family, only Cers3 mRNA expression was limited to germ cells, where it was up-regulated more than 700-fold during postnatal testicular maturation. Increasing levels of neutral complex VLC-PUFA GSLs also correlated with the progression of spermatogenesis in a series of male sterile mutants with arrests at different stages of spermatogenesis. Remarkably, fucosylation of the complex VLC-PUFA GSLs was not essential for spermatogenesis, as fucosylation-deficient mice produced nonfucosylated versions of the complex testicular VLC-PUFA GSLs, had complete spermatogenesis, and were fertile. Nevertheless, sterile Galgt1(-/-) mice, with a defective meiotic cytokinesis and a subsequent block in spermiogenesis, lacked complex but contained simple VLC-PUFA GSLs, as well as VLC-PUFA ceramides and sphingomyelins, indicating that the latter lipids are not sufficient for completion of spermatogenesis. Thus, our data imply that both glycans and the particular acyl chains of germinal sphingolipids are relevant for proper completion of meiosis.     

Quantitative analysis of neutral glycosphingolipids from human lymphocyte subpopulations.

The glycosphingolipids of normal human lymphocytes from individual donors were analysed by high-pressure liquid chromatography. In addition, purified T- and B-lymphocytes were examined separately. Lactosylceramide was shown to be the major neutral glycosphingolipid in human lymphocytes, and monohexosylceramide, trihexosylceramide, globoside and paragloboside were all detected in smaller amounts. Analysis of purified B- and T-cell fractions revealed that each of these populations contained a similar qualitative profile for neutral glycosphingolipids, but that quantitatively, B-cells contained several times more of each glycosphingolipid per cell than did T-cells.     

Association of glycosphingolipids with intermediate filaments of mesenchymal, epithelial, glial, and muscle cells.

We reported recently that two glycosphingolipids (GSLs), globoside (Gb4) and ganglioside GM3, colocalized with vimentin intermediate filaments of human umbilical vein endothelial cells. To determine whether this association is unique to endothelial cells or to vimentin, we analyzed a variety of cell types. Double-label immunofluorescent staining of fixed, permeabilized cells, with and without colcemid treatment, was performed with antibodies against glycolipids and intermediate filaments. Globoside colocalized with vimentin in human and mouse fibroblasts, with desmin in smooth muscle cells, with keratin in keratinocytes and hepatoma cells, and with glial fibrillary acidic protein (GFAP) in glial cells. Globoside colocalization was detected only with vimentin in MDCK and HeLa cells, which contain separate vimentin and keratin networks. GM3 ganglioside also colocalized with vimentin in human fibroblasts. Association of other GSLs with intermediate filaments was not detected by immunofluorescence, but all cell GSLs were detected in cytoskeletal fractions of metabolically labelled endothelial cells. These observations indicate that globoside colocalizes with vimentin, desmin, kertain and GFAP, with a preference for vimentin in cells that contain both vimentin and keratin networks. The nature of the association is not yet known. Globoside and GM3 may be present in vesicles associated with intermediate filaments (IF), or bound directly to IF or IF associated proteins. The prevalence of this association suggests that colocalization of globoside with the intermediate filament network has functional significance. We are investigating the possibility that intermediate filaments participate in the intracellular transport and sorting of glycosphingolipids.     

Glycosphingolipids of human urothelial cell lines with different grades of transformation

Neutral glycolipids and gangliosides from seven human urothelial cell lines, differing in grades of transformation (TGr), were characterized by fast atom bombardment mass spectrometry, exoglycosidase treatment and an immunostaining procedure. The major neutral glycolipids identified in all cell lines studied included CMH, CDH, CTH, globoside and paragloboside, the gangliosides were G_M3, G_M2, sialosylparagloboside and G_D1a. The following observations were made: 1. G_M2 was the major ganglioside in the TGrll cell lines (non-tumorigenic, non-invasive), but a minor component in the TGrIII cell lines (tumorigenic, invasive). 2. All components showed C16:0 and C24:0 as major fatty acids, but in the TGrIII cell lines the fatty acid composition of CMH and some of the gangliosides were more complex showing unsaturated and hydroxy-fatty, acids as well.Abbreviations CMH Monohexosylceramide - CDH Lactosylceramide (Galß1-4GlcCer) - CTH Globotriaosylceramide (Gal1-4Galß1-4GlcCer) - Globoside (GalNAcß1-3Gal1-4Galß1-4GlcCer) - Paragloboside (Galß1-4GlcNacß1-3Galß1-4GlcCer) - 3L_M1 Slalosylparagloboside (Neu5Ac2-3Galß1-4GlcNacß1-3Galß1-4GlcCer) - Aslalo-G_M2 (GalNAcß1-4Galß1-4GlcCer) - AsialoG_M1 (Galß1-3GalNAcß1-4Galß1-4GlcCer) - Hex Hexosyl - HexNAc 2-acetamido-2-deoxyhexosyl - HPTLC high performance thin layer chromatography - FAB-MS fastatom bombardment mass spectrometry - TGr transformation grade Ganglios are named according to Svennerholm [1]     

Differentiation-associated changes of glycolipid composition and metabolism in mouse myeloid leukemia cells. Induction of globotriaosylceramide and a galactosyltransferase

This study was to find out whether induction of special glycolipids or glycosyltransferases for glycolipid synthesis which might be involved in the cell functions occurred during the differentiation. Mouse myeloid leukemia cell line (M1-), the differentiated cells (M1+), and a subcloned cell line (Mm1) were used for this purpose. Gangliotriaosylceramide (GA2) was the major glycolipid component in M1- cells. As a result of differentiation of M1- into M1+ cells, globotriaosylceramide (CTH) was newly induced as the main glycolipid, while GA2 decreased to a minor component. GA2 was found to be the main glycolipid in Mm1 cells but no CTH was recognized. All precursor glycolipids and glycosyltransferases required to complete the biosynthetic pathway glucosylceramide (CMH) leads to lactosylceramide (CDH) leads to GA2 leads to gangliotetraosylceramide (GA1) leads to sialosylgangliotetraosylceramide (GM1b) were found in M1- and also in Mm1 cells. A galactosyltransferase activity for CTH synthesis from CDH increased 10 fold during the differentiation. The induction of CTH in M1+ cells could be attributed to the increase of the galactosyltransferase activity. Both CTH as a surface marker and the galactosyltransferase as an enzyme marker are proposed as valuable markers of differentiation in M1- cells. Besides the galactosyltransferase, N-acetylglucosaminyltransferease involved in the formation of lactotriaosylceramide (amino-CTH) increased up to 3 fold during the differentiation. The increase of the enzyme activity seemed to be responsible for the biosynthesis of lactoneotetraosylceramide (paragloboside) which appeared in M1+ cells.     

Structural analysis of neutral glycosphingolipids from Ascaris suum adults (Nematoda: Ascaridida)

The neutral glycosphingolipid fraction from adults of the pig parasitic nematode, Ascaris suum, was resolved into four components on thin-layer chromatography. The high-performance liquid chromatography-isolated components were structurally analysed by: methylation analysis; exoglycosidase cleavage; gas-liquid chromatography/mass spectrometry; liquid secondary-ion mass spectrometry; and, in particular, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Their chemical structures were determined as: Glc(β1-1)ceramide, Man(β1-4)Glc(β1-1)ceramide, GlcNAc(β1-3)Man(β1-4)Glc(β1-1)ceramide and Gal(α1-3)GalNAc(β1-4)GlcNAc(β1-3)Man(β1-4)Glc(β1-1)ceramide; and were characterized as belonging to the arthro-series of protostomial glycosphingolipids. No glycosphingolipid component corresponding to ceramide tetrasaccharide was detected during these analyses. The ceramide composition of the parent glycosphingolipids was dominated by the 2-(R)-hydroxy C24:0 fatty acid, cerebronic acid, and C17 sphingoid-bases: 15-methylhexadecasphing-4-enine and 15-methylhexadecaphinganine in approximately equal proportions. The component ceramide monohexoside was characterized by an additional 15-methylhexadecaphytosphingosine. Abbreviations: CDH, ceramide dihexoside; Cer, ceramide; CMH, ceramide monohexoside; CPH, ceramide pentahexoside; CTH, ceramide trihexoside; CTetH, ceramide tetrahexoside; Hex, hexose; HexNAc, N-acetylhexosamine; HPTLC, high-performance thin-layer chromatography; LSIMS, liquid secondary-ion mass spectrometry; MALDI-TOF-MS, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; N-, Nz- and A-glyco(sphingo)lipids, neutral, neutralzwitterionic and acidic glyco(sphingo)lipids, respectively This revised version was published online in November 2006 with corrections to the Cover Date.     

Exposure of major glycolipids in human Pk and p erythrocytes

The exposure of glycolipids in P^k and p red cells was studied by the galactose oxidase/ NaB²H₄ and galactose oxidase/NaB³H₄ surface labeling techniques. The major glycolipid in P^k cells, ceramide trihexoside was efficiently labeled when high amounts of galactose oxidase were used. In contrast, the major glycolipid in p cells, ceramide dihexoside was not oxidized by galactose oxidase. However, minor components with longer oligosaccharide chains were readily labeled in p cells by the galactose oxidase/NaB³H₄ method.Abbreviations CDH ceramide dihexoside, LacCer - CTH ceramide trihexoside, GbOse₃Cer     

Glycosphingolipids of Human Peripheral Nervous System Myelins Isolated from Cauda Equina

Abstract: Compositions of neutral and sulfated glucuronyl glycosphingolipids purified from human motor and sensory nerves and myelins were studied. Higher neutral glycosphingolipids (fraction B), which were separated from GazlCer (fraction A), were analyzed by TLC and TLC-immunostaining. Both nerve myelins contained paragloboside (nLc₄Cer) and nLc₆Cer dominantly as major higher glycosphingolipids and very little globoside (Gb₄Cer), whereas both nerves contained Gb₄Cer and nLc₄Cer. Besides these major glycosphingolipids, a neutral glycolipid containing asialoGMI (Gg₄Cer) epitope and other minor components such as ceramide trihexoside and ceramide dihexoside were detected in both nerves and their myelins. Furthermore, sulfated glucuronyl nLc₄Cer and n Lc₆Cer, which were monoclonal antibody HNK-1 reactive glycolipids, were detected in both nerves and myelins.