Glycolipids of fetal, newborn, and adult erythrocytes: glycolipid pattern and structural study of H3-glycolipid from newborn erythrocytes

The glycolipids of blood group type O adult, newborn, and fetal erythrocytes were compared. The total amount of glycolipids was indistinguishable between adult and newborn erythrocytes. However, glycolipids with long and neutral carbohydrates and the H determinant were greatly reduced in newborn cells. On the other hand, the amount of sialylated glycolipids (gangliosides) was significantly higher in newborn cells, suggesting that during erythropoiesis sialyltransferases are more active in fetuses than in adults. The amount of each core structure, lacto-N-tetraosyl, linear lacto-N-hexaosyl, and branched lacto-N-octaosyl, was compared between adult and newborn erythrocytes. It was found that branched lacto-series glycolipids were reduced in newborn cells compared with adult cells. Thus, development from fetal to adult human erythrocytes is associated with an increase of branching and a decrease of sialylation of N-acetyllactosaminyl carbohydrate chains. The study indicates that glycolipids are quantitatively different between adult and newborn or fetus.     

CD1d ligands: the good, the bad, and the ugly

The MHC class I-like CD1d glycoprotein is a member of the CD1 family of Ag-presenting molecules and is responsible for the selection of NKT cells. A number of ligands that can be presented by CD1d to NKT or other CD1d-restricted T cells have been identified. These include glycolipids from a marine sponge, bacterial glycolipids, normal endogenous glycolipids, tumor-derived phospholipids and glycolipids, and nonlipidic molecules. The presentation of many of these molecules can have immunopotentiating effects, such as serving as an adjuvant against malaria or resulting in a more rapid clearance of certain virus infections. They can also be protective in autoimmune diseases or cancer or can be deleterious. This review will highlight these ligands in a discussion of their potential use against (and role in the pathogenesis of) these diseases.     

Synthesis, biological studies of linear and branched arabinofuranoside-containing glycolipids and their interaction with surfactant protein A

Oligoarabinofuranoside-containing glycolipids relevant to mycobacterial cell wall components were synthesized in order to understand the functional roles of such glycolipids. A series of linear tetra-, hexa-, octa- and a branched heptasaccharide oligoarabinofuranosides, with 1?→?2 and 1?→?5 α-linkages between the furanoside residues, were synthesized by chemical methods from readily available monomer building blocks. Upon the synthesis of glycolipids, constituted with a double alkyl chain-substituted sn-glycerol core and oligosaccharide fragments, biological studies were performed to identify the effect of synthetic glycolipids on the biofilm formation and sliding motilities of Mycobacterium smegmatis. Synthetic glycolipids and arabinofuranosides displayed an inhibitory effect on the growth profile, but mostly on the biofilm formation and maturation. Similarly, synthetic compounds also influenced the sliding motility of the bacteria. Further, biophysical studies were undertaken, so as to identify the interactions of the glycolipids with a pulmonary surfactant protein, namely surfactant protein A (SP-A), with the aid of the surface plasmon resonance technique. Specificities of each glycolipid interacting with SP-A were thus evaluated. From this study, glycolipids were found to exhibit higher apparent association constants than the corresponding oligosaccharide portion alone, without the double alkyl group-substituted glycerol core.     

Neutral glycosphingolipids of ova of the fresh-water bivalve, Hyriopsis schlegelii

The neutral glycosphingolipids of ova of the fresh-water bivalve, Hyriopsis schlegelii were characterized. The most abundant glycolipid was ceramide monosaccharide, followed by ceramide trisaccharide, ceramide tetrasaccharide, and ceramide disaccharide. More complex neutral glycolipids accounted for almost one-third of the total. The total amount of these glycolipids was 0.59 mg/g of dry weight of the ova preparation, a yield which was one-seventh of that of spermatozoa neutral glycolipids. Structural analyses were performed by enzymatic hydrolysis of the glycolipids with exoglycosidases, permethylation experiments, and also immuno-chemical assays. The proposed structures are as follows: ceramide monosaccharides, Gal-Cer and Glc-Cer; ceramide disacharides, Gal(beta 1-4)Gal-Cer, Gal(beta 1-4)Glc-Cer, and Man(beta 1-4)Glc-Cer; ceramide trisaccharide, Man(alpha 1-3)Man(beta 1-4)Glc-Cer; ceramide tetrasaccharides, Man(alpha 1-3)[Xyl(beta 1-2)]Man(beta 1-4)Glc-Cer, GlcNAc(beta 1-2)Man(alpha 1-3)Man(beta 1-4)Glc-Cer, Man(alpha 1-3)[Gal(beta 1-2)]Man(beta 1-4)Glc-Cer, and Man(alpha 1-2?)Man(alpha 1-3)Man(beta 1-4)Glc-Cer. The latter two ceramide tetrasaccharides were new types of glycosphingolipids. The spectrum of ova glycolipids appeared to be more complicated than that of the spermatozoa glycolipids. The ova glycolipids characterized here, with the exception of ceramide tetrasaccharides, contained considerable amounts of 2-hydroxy fatty acids, which were not observed in the spermatozoa glycolipids. The major sphingosine base was C18-sphingenine in all the ova glycolipids as well as in the spermatozoa glycolipids. However, the content of anteiso type of sphingosine base was 2- to 3-fold higher in the ova than in the spermatozoa.     

Polarity of neutral glycolipids, gangliosides, and sulfated lipids in MDCK epithelial cells

Confluent monolayers of MDCK (Madin-Darby canine kidney) cells provide a widely used model system for studying epithelial cell polarity. We determined the polarity of epithelial cell plasma membrane glycolipids and sulfated lipids by analyzing the lipids released from both sides of monolayers of metabolically labeled MDCK cells. These lipids were released either as endogenously shed material or in budding viruses. All of the glycolipids were detected in both the apical and basolateral domains of the plasma membrane. However, galactosylceramide was more basally oriented than any of the other glycolipids; thus, the ratio of glucosylceramide to galactosylceramide was more than twice as great in the apical domain as in the basolateral domain. A sulfated sterol, which comigrated with cholesterol sulfate, was released in a more basally polarized manner than any of the glycolipids. These results indicate the presence of mechanisms which can produce different degrees of polarity for specific lipids in polarized epithelial cells.     

A basidiomycetous yeast, Pseudozyma crassa, produces novel diastereomers of conventional mannosylerythritol lipids as glycolipid biosurfactants

Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by the yeast strains of the genus Pseudozyma. These compounds show not only excellent surface-active properties, but also versatile biochemical actions. During a survey of new MEL producers, we found that a basidiomycetous yeast, Pseudozyma crassa, extracellularly produces three glycolipids. When glucose and oleic acid were used as the carbon source, the total amount of glycolipids reached approximately 4.6 g/L in the culture medium. The structures of these glycolipids were similar to those of well-known MEL-A, -B, and -C, respectively. Very interestingly, in all the present glycolipids, the configuration of the erythritol moiety was entirely opposite to that of conventional MELs. The present glycolipids were identified to have the carbohydrate structure of 4-O-β-d-mannopyranosyl-(2R,3S)-erythritol, stereochemically different from 4-O-β-d-mannopyranosyl-(2S,3R)-erythritol of conventional MELs. Furthermore, these new glycolipids possessed both short-chain acids (C₂ or C₄) and long-chain acids (C₁₄, C₁₆, or C₁₈) on the mannose moiety. The major component of the present glycolipids clearly showed different interfacial and biological properties, compared to conventional MELs comprising two medium-chain acids on the mannose moiety. Accordingly, the novel MEL diastereomers produced by P. crassa should provide us with different glycolipid functions, and facilitate a broad range of applications of MELs.     

Possible role of macrophage glycolipids as receptors for migration inhibitory factor (MIF).

Guinea pig peritoneal exudate cells incubated with water soluble glycolipids obtained from macrophages show an enhanced response to migration inhibitory factor. Incorporation of these glycolipids into liposomes greatly facilitates their interaction with indicator cells. Enhancement of peritoneal exudate cell responsiveness to migration inhibitory factor was specific for glycolipids from guinea pig macrophages. Glycolipids extracted from guinea pig brain and polymorphonuclear leukocytes as well as several bovine and porcine glycolipids had no effect. Specificity of enhancement was not due merely to a preferential association of macrophage glycolipids with indicator cells. The possible role of macrophage glycolipids as receptors for MIF is discussed.     

Mannosylerythritol lipid, a yeast extracellular glycolipid, shows high binding affinity towards human immunoglobulin G

Background  

There have been many attempts to develop new materials with stability and high affinity towards immunoglobulins. Some of glycolipids such as gangliosides exhibit a high affinity toward immunoglobulins. However, it is considerably difficult to develop these glycolipids into the practical separation ligand due to their limited amounts. We thus focused our attention on the feasible use of "mannosylerythritol lipid A", a yeast glycolipid biosurfactant, as an alternative ligand for immunoglobulins, and undertook the investigation on the binding between mannosylerythritol lipid A (MEL-A) and human immunoglobulin G (HIgG).     

Isolation, initial characterization and serological studies of glycolipid antigens from Babesia bovis-infected erythrocytes

Serological analysis of Babesia bovis-derived glycolipids by ELISA and the indirect fluorescent antibody technique demonstrated the existence of their antigenic and immunogenic activities not only in B. bovis but also in B. bigemina infections. This indicates that serological cross-reactivity of B. bovis and B. bigemina relates to glycolipids. The negative ELISA reaction obtained with Anaplasma marginale antisera suggested the specificity of the reaction to the genus Babesia. Fractionation of these glycolipids by Florisil Sep-Pak column chromatography with subsequent HPTLC immunostaining and Orcinol staining suggested the presence of carbohydrate antigenic determinants in B. bovis glycolipids.     

Seeds of Trichosanthes kirilowii, an energy-rich diet

The kernels of Trichosanthes kirilowii seeds contain a green oil which makes up for 62% of their dry matter. This oil consists up to 95% of triglycerides, 2% of glycolipids, 1.3% of phospholipids and 1.8% of chlorophylls. As fatty acid components the triglycerides, glycolipids and phospholipids contain the unsaturated fatty acids linoleic and oleic acid and the saturated palmitic acid. In the triglycerides 19% of the C18:3 acid occur with the configuration delta9 cis, delta11 trans, delta13 cis. This acid is called trichosanic acid and is absent in glycolipids and phospholipids which contain instead another C18:3 fatty acid, which has conjugated double bounds and occurs with an amount of 21% and 3%, respectively. Typically, these oil seeds contain in addition up to 30% of their dry matter proteins and up to 2.5% mono- and oligosaccharides. The monosaccharides consist of rhamnose, galactose and glucose and the oligosaccharides represent a mixture of tri- and tetrasaccharides.     

Chemical distribution of glycosphingolipids in third-instar larval organs of the blowfly, Calliphora vicina (Insecta: Diptera).

As a first approach to testing the working hypothesis that glycosphingolipids are functionally involved in the ontogeny of insects, their chemical distribution in larval organs was determined and any stadium-correlated differences documented. Selected organs, i.e., the fatbody, striated muscle, intestinal tract, salivary glands, imaginal discs, and central nervous system, were dissected from seven-day-old larvae of the blowfly, Calliphora vicina, and their glycolipids isolated. Two-dimensional, high-performance thin-layer chromatography was used to separate the neutral and acidic glycolipids of each organ. Significantly different total glycolipid component-patterns were obtained for the individual organs, whereby, except for a number of additional uncharacterized components in the intestinal tract, the neutral glycolipids of all organs were found to be qualitatively similar. However, major quantitative differences between the selected organs were found in their total glycolipid-carbohydrate contents, as well as the respective quantitative neutral glycosphingolipid-component distributions. The acidic glycolipids showed pronounced qualitative as well as quantitative organ-dependent variations. Whereas the highest proportion of uncharged glycolipids was characteristic of the fatbody, a high proportion of zwitterionic glycolipid-components was observed to be typical of the central nervous system and imaginal discs, i.e., of organs persisting during larval life and throughout metamorphosis. Imaginal disc glycolipids were distinguished by their high content of acidic glycolipids, a putative reflection of the functional role of these glycoconjugates in regulated cell reorganization during metamorphosis.     

Functional significance of glycolipid as an important plasma membrane constituent

Glycolipids are ubiquitous membrane components in various mammalian cells and participate in several functions through membrane. Until now, about 180 glycolipids with different carbohydrate structures have been characterized. Since alteration in glycolipids during cellular proliferation, differentiation and transformation is dramatic in general, several approaches have been attempted to clarify the meaning. Our findings that ganglioside composition in human milk is characteristically changed during the periods of lactation and that N-(O-linoleoyl-omega-hydroxylignoceroyl) sphingosyl glucose (ester CMH) in mammalian skin is characteristically synthesized during differentiation of epidermis are the examples to indicate the close association of glycolipids in cellular functions. GM3 ganglioside appeared in the later period of lactation has an activity to suppress cell growth of human breast cancer and ester CMH has an activity to promote the keratinization of epidermal cells, respectively. The observations indicate that glycolipids synthesized during cellular differentiation function as an signal transducer through plasma membrane. Structural bases of glycolipids to give such physiological activities are summarized and discussed in this communication.     

Glycosphingolipids of human myometrium and endometrium and their changes during the menstrual cycle, pregnancy and ageing

The glycolipid composition of human myometrium and endometrium was examined at various stages of maturation and reproduction. The major neutral glycolipids of both myometrium and endometrium were identified by high-performance thin-layer chromatography as globo-series glycolipids, Gb3 and Gb4. The major acidic glycolipids (gangliosides) were identified similarly as GM3 and GD3, with lesser amounts of GM1, GD1a, and GT1b. During pregnancy, GD3 expression declined in both myometrium and endometrium, whereas GM3 expression increased. Reciprocal changes in GM3/GD3 expression were mirrored by appropriate changes in the glycosyltransferases required for their synthesis; alpha 2----3sialyltransferase activity increased approximately 3-fold during pregnancy, while alpha 2----8sialyltransferase activity declined to about 20%. The results focus attention on the glycolipids of uterine tissues, their regulation, and their possible role in reproduction and fertility.     

Structure of mycoside F, a family of trehalose-containing glycolipids of Mycobacterium fortuitum

Nuclear magnetic resonance spectroscopy, fast-atom bombardment mass spectrometry, gas chromatography-mass spectrometry, as well as chemical degradations were used to elucidate the structure of the major glycolipids of Mycobacterium fortuitum. Three main glycoconjugates were detected and their structures established as 2,3-diacyl, 2,3,4- and 2,3,6-triacyl trehalose. The characteristic infrared spectrum which led to their original designation as mycoside F, a family of glycolipids limited in distribution to M. fortuitum, was due to the nature of the fatty acyl substiuents identified primarily as 2-methyl-octadecen-2-oyl. The antigenic glycolipids typified the biovar. fortuitum, thus allowing its easy recognition from the C-mycoside glycopeptidolipid-containing biovar. peregrinum.     

Glycolipid stage-specific embryonic antigens (SSEA-1) in kidneys of male and female C57BL/6J and beige adult mice

SSEA-1 glycolipids from the kidneys of normal male and female as well as beige mutant mice were isolated and their structures were examined by component analysis, mass spectrometry, immunoblotting, and permethylation studies. These antigens were shown to be extended globoside derivatives as reported by Sekine et al. (1987. J. Biochem. 101:553-562). Quantitative high performance liquid chromatography analyses revealed that the concentration of SSEA-1 glycolipids were four-to fivefold greater in male than female mice. Essentially no SSEA-1 glycolipids were excreted in the urine of normal male mice and thus are not components of the multilamellar lysosomes normally excreted. Testosterone is known to induce the hypertrophy of proximal tubule cells that involves the formation of multilamellar lysosomes and results in the accumulation and excretion of these bodies and associated lysosomal enzymes and specific glycolipids. The present results indicate that in male mice there is also an increase in subcellular structures that contain SSEA-1 glycolipids. The amount of SSEA-1 glycolipids in male beige mice were greater than in normal mice on a per kidney basis. Thus, the increase is in proportion to the kidney hypertrophy seen in beige mouse kidneys. Beige mutant mice appear to have a primary defect in the excretion of multilamellar lysosomes which produces a secondary hypertrophy with an accompanying increase in SSEA-1 glycolipids.     

Analysis of glycosphingolipid-derived oligosaccharides by high pH anion exchange chromatography

As an adjunct to existing thin layer and column chromatographic methods for the identification of glycolipids a method that utilizes the high pH anion chromatographic (HPAEC) analysis of the oligosaccharides released from the glycolipids by endoglycoceramidase has been developed. Using a Dionex Carbo Pak PA1 column and elution with a linear gradient of sodium acetate in 0.2M NaOH, the elution times of eight neutral and fourteen acidic oligosaccharides derived from glycolipids were determined. Under these conditions the neutral oligosaccharides were well separated from each other but some of the acidic oligosaccharides had overlapping elution times. The ganglioside-derived oligosaccharides could be further identified by treating them with sialidase or by mild acid hydrolysis and reanalysing the products by HPAEC. The method was applied to the analysis of mixed bovine brain gangliosides. The procedure provides an additional approach for the initial identification of glycolipids by analysing the component oligosaccharides rather than the intact glycolipids.     

Composition of lipids in roots, stalks, leaves and flowers of Eichhornia crassipes (Mart.) Solms

The lipid contents of the roots, leaf stalks, leaves and flowers of Eichhornia crassipes (Mart.) Solms (water-hyacinth) were 1.6, 0.9, 14.9 and 5.7%, respectively, on a dry-weight basis. Non-polar lipids were half the total, while glycolipids and phospholipids in approximately equal proportions constituted the remainder, except in leaf stalks, where glycolipids were a larger fraction. Among the non-polar lipids, triacyglycerols predominated, except for pigments in the leaves. Monogalactosyldiglycerides and digalactosyldiglycerides were the major glycolipids. The main phospholipids were phosphatidylcholine in the roots, phosphatidylglycerol in the leaf stalks and leaves, and phosphatidylethanolamine in the flowers. The major fatty acids were palmitic and linoleic in the roots, linoleic in the leaf stalks, palmitic in the leaves, and linolenic and linoleic in the flowers.     

Computer modelling of glycolipids at membrane surfaces.

Interactions of membrane anchored molecules such as glycolipids with a membrane surface are important in determining headgroup conformation. It is therefore essential to represent these membrane surface interactions in molecular modeling studies of glycolipids and other membrane bound molecules. We introduce here an energy term that represents the interaction of molecules with a membrane bilayer. This membrane interaction energy term has been added to the potential energy function of a molecular dynamics and mechanics program and has been parameterized using partition coefficients between an aqueous solution and a vesicular membrane for two model glycolipids.     

Direct detection of Mycobacterium tuberculosis lipid antigens by thin-layer chromatography

Abstract Free lipids were extracted from Mycobacterium tuberculosis H37Rv, and their antigenicity was assessed directly on thin-layer chromatograms (TLC) by an immunostaining technique. A family of glycolipids, composed of trehalose acylated with multimethyl branched long-chain fatty acids, was investigated. The most polar of these glycolipids was identified as a possible specific surface antigen. A pair of novel polar glycolipids also showed positive antigenic reactions.     

Design, synthesis and biological evaluation of novel lipoamino acid-based glycolipids for oral drug delivery

A series of lipoamino acid-based glycolipids were synthesised. Suitably derivatised lipoamino acid derivatives were prepared and conjugated to monosaccharides (including glycosyl azides, isothiocyanates, thiols and sulphones) to yield novel O-, N-, S- and C-linked glycolipids in good yields. Their potential to improve the oral absorption of piperacillin is reported.