Glycolipids

12 Key excerpts on "Glycolipids"

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  Lipid Analysis

  • Prof F W Hemming, Dr J N Hawthorne(Authors)
  • 2020(Publication Date)
  • Garland Science

    (Publisher)

  8 Glycolipids

  The broad definition of Glycolipids as compounds containing carbohydrate covalently linked to a lipid-soluble moiety encompasses a wide range of substances. This broad group can be divided conveniently into four subgroups: glycosphingolipids, polyisoprenyl phosphosugars, glycosylglycerides and lipoteichoic acids.

  8.1 Glycosphingolipids

  8.1.1 Biological significance

  These compounds are found as components of the outer leaflet of the plasma membrane of animal cells. A hydrophobic ceramide portion anchors a hydrophilic oligosaccharide chain to the surface of the cell. The expression of these compounds is often specific to a particular cell type or developmental stage. Their location and diversity of structure makes them well suited to a role in cell surface recognition. Examples of this function can be found in leukocyte adhesion to vascular endothelium, which involves the binding of proteins such as ELAM-1 (E-selectin) to carbohydrate determinants of glycosphingolipids [1 ]. Also important is the involvement of glycosphingolipids in neural cell-cell and cell-substratum recognition and adhesion.

  Glycosphingolipids have also been reported (see e.g. ref. 1 ) to influence the activity of proteins in the same plasma membrane (cis-regulation) and in apposing membranes (trans-regulation). The proteins concerned are generally cell-surface receptors. It is thought that this may allow modulation of cell growth and differentiation, especially in developing nerve tissue.

  The presence of glycosphingolipids as recognition and binding molecules at the cell surface provides several pathogenic organisms with convenient targets when invading cells. Several viruses have been reported to use host glycosphingolipids as adherence sites on host cell surfaces. This sort of phenomenon has also been implicated in the initiation of infection of host cells by bacteria. In some cases, for example cholera toxin, the protein exotocin released by bacteria gains entry to the target cell by first binding to a specific glycosphingolipid (ganglioside GM1

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  Carbohydrate Chemistry

  Volume 40

  • Amelia Pilar Rauter, Thisbe Lindhorst, Yves Queneau(Authors)
  • 2014(Publication Date)
  • Royal Society of Chemistry

    (Publisher)

  Glycolipids are particularly suited to multivalent interactions due to their mobility and their ability to interact laterally within the membrane plane, both as hydrogen bond donors and as acceptors. In addition to their role in recognition phenomena, Glycolipids may also affect the physical properties of lipid membranes. Noteworthy, glycosylated lipids are thought to influence the formation of microdomains and lipid rafts. 4 Furthermore, the high proportions of Glycolipids present in some extre-mophilic Archaea were shown to strongly stabilize the membrane struc-ture by interglycosyl headgroup hydrogen bondings. 5,6 The finding that Glycolipids may exert a positive impact on cell mem-branes in terms of physical and cell-surface recognition properties led to the idea that they could be advantageously incorporated into nanosys-tems for drug and gene delivery applications. Typically, Glycolipids were introduced into lipid bilayers to provide nano-assemblies termed glyco-liposomes and glycovesicles (Fig. 1). 7,8 In particular, nanosystems con-taining natural or synthetic Glycolipids were investigated for targeting drugs and genes to specific disease cells via carbohydrate-lectin inter-actions. The presence of targeting carbohydrate ligands could further enhance cellular uptake and retention of drugs via receptor-mediated endocytosis, which is particularly essential for the delivery of substances that require intracellular delivery for bioactivity. It has been also shown that strong adjuvant activities could be exhibited by the incorporation of synthetic Glycolipids into vaccine liposomal formulations. Interestingly, subtle variations in the carbohydrate head group were found to alter the type and potency of immune responses.

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  Polysaccharides

  Structural Diversity and Functional Versatility, Second Edition

  • Severian Dumitriu(Author)
  • 2004(Publication Date)
  • CRC Press

    (Publisher)

  32 Crystal Structures of Glycolipids Yutaka Abe Process Development Research Center, Lion Corporation, Tokyo, Japan Kazuaki Harata Biological Information Research Center, National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan I. INTRODUCTION Glycolipids are very important functional materials for daily life and human activity. The Glycolipids play roles as the structural holder of membrane proteins suspended in bilayer or bicontinuous cubic phases, and as the key code of the intercellular communication or immune system. The definition of Glycolipids could be expanded to amphi-philes with sugar moieties as those with hydrophilic heads. These materials are commonly used for industry and are necessary for human life. In the area of consumer prod-ucts, Glycolipids are used as main ingredients in detergents for the kitchen and emulsifiers of foods and cosmetics— where their excellent surface activity are advantageously utilized. In the area of biochemical research, Glycolipids are key compounds for dissolving and crystallizing mem-brane proteins. It is quite natural that organs produce amphiphiles with a combination of sugar and lipid moieties for hydro-philic and hydrophobic components, respectively. It is an important assignment for researchers focusing on glyco-lipids to clarify the functional mechanism of sugar moie-ties in its molecular assembly from the physicochemical viewpoint. We have been focusing on the crystal structures of Glycolipids to understand the role of sugar moieties in the molecular assembly. First, crystal is a phase of the molec-ular assembly, and it is similar to the molecular arrange-ment of the liquid crystal in solution. Second, we can quantitatively clarify the functions and effects of the sugar moieties by analyzing the detailed crystal structure from the coordinate. The most important function of the sugar moieties is the formation of hydrogen-bonding.

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  Introduction to Lipidomics

  From Bacteria to Man

  • Claude Leray(Author)
  • 2012(Publication Date)
  • CRC Press

    (Publisher)

  247 5 Complex Glycolipids Complex.Glycolipids.are.formed.of.various.types.of.simple.lipids,.secondarily.bound. to.a.glycanic.residue.of.various.composition,.and.they.may.also.be.phosphorylated . . They.are.thus.generally.glycosylated.derivatives.of.acylglycerols,.ceramides,.or.pre-nylated.lipids . .They.represent.a.very.heterogeneous.group.of.lipid.compounds.present. from.the.most.primitive.bacteria.to.man . .The.glucidic.polar.group.of.these.glyco-lipids.is.frequently.similar.to.the.carbohydrate.moieties.of.the.glycocalyx.coating.of. the.cell.surface . .Their.implications.in.cellular.physiology.are.also.quite.diversified,. because.they.are.associated.with.membrane.proteins.and.involved.in.the.intercellu-lar.signaling.and.the.regulation.of.transmembrane.signals . .The.Glycolipids.are.thus. important.actors.in.the.initiation.of.mitogenesis,.morphogenesis,.and.the.recognition. mechanisms.linked.to.the.immune.system . .These.are.also.key.components.of.the. membranes,.protecting.cells.against.chemical.aggression.from.the.external.medium . The.lipid.part.of.these.Glycolipids.is.generally.formed.of.a.diacylglycerol.in.bac-teria.and.plants,.and.of.a.ceramide.in.animals . .More.complex.Glycolipids,.the.lipo-polysaccharides,.the.glycopeptidolipids,.and.the.phenolic.Glycolipids.are.also.present. in.bacteria . Here,.we.will.adopt.the.nomenclature.recommended.in.1997.by.the.International. Union.for.Pure.and.Applied.Chemistry.(IUPAC) . According. to. their. structure,. the. complex. Glycolipids. can. thus. be. classified. according.to.whether.their.lipidic.part.consists.of.the.following: •. Diacylglycerol —Glycoglycerolipids.(Section.5 .1) •. Ceramide —Glycosphingolipids.(Section.5 .2) •. Fatty acids linked to a phosphorylated oligosaccharide —Lipo. poly-saccharides.(Section.5 .3) •. Fatty acids linked to a glycosylated phenolic alcohol —Phenolic.glycolip-ids.(Section.5 .4) •.

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  Introduction to Modern Biochemistry 3e

  • P Karlson(Author)
  • 1975(Publication Date)
  • Academic Press

    (Publisher)

  C H A P T E R XIII Phospholipids, Glycolipids, and Membranes Structure and function of biological membranes is an area of biochemistry that in recent years has become increasingly prominent. Many cell properties are determined by the surface of cell membranes. Moreover, within cells numerous membranes form various compartments of the cell (see Chapter XVIII) and many of these membranes also contain structure-bound enzymes, as already seen in the case of the respiratory chain and the microsomal hydroxylation system. The intensive interest in the study of biological membranes thus is well justified. Membranes are formed of proteins and lipids, particularly phospho- and Glycolipids. The latter possess both hydrophobic and hydrophilic groups in one molecule and, therefore, in aqueous media spontaneously form ordered structures called micelles. These properties are essential also for the structure of biological membranes. Originally the term lipid was applied to all substances with solubility properties similar to those of fats. In addition to phospholipids and Glycolipids, lipids also include sterols and several isoprenoid lipids, which will be discussed in Chapter XIV. First we will present the biochemistry of phospho- and Glycolipids and derive the various characteristic structures on the basis of their biosynthetic pathways. 1. Structural Features Phospholipids, often called phosphatides, chemically are phosphodiesters. Phosphoric acid is esterified on the one side with a derivative of either sphingosine or glycerol (usually diacylglycerol) and on the other side with either choline, ethanol-amine, serine, inositol, or another glycerol. The three components choline, ethanol-amine, and serine contain basic nitrogen which bears a positive charge at physiological pH. And since the phosphate group has a negative charge, phosphatides are amphoteric (zwitterions). 253

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  The Carbohydrates

  Chemistry And Biochemistry

  • Ward Pigman(Author)
  • 2012(Publication Date)
  • Academic Press

    (Publisher)

  The func-tion of these substances is relatively obscure in comparison to the definitive 711 712 JOHN M. MCKIBBIN function of many other substances familiar to the molecular biologist. How-ever, they doubtless contribute certain significant chemical and structural properties to their parent lipoproteins. Myelin Glycolipids, for example, by virtue of their structural peculiarities may serve as a major contributor to the stability of the membranous unit. In addition, the Glycolipids have a broad spectrum of haptenic activity, show distinct distribution patterns in organs of an animal species and between species, and could play some part in cellular recognition. A number of excellent recent reviews deal comprehensively with various aspects of this subject. The reader may refer to general reviews by Law 1 and by Carter et al. 2 Other reviews will be listed below in the appro-priate section. II. NOMENCLATURE OF Glycolipids Glycolipids are named within the framework of the Rules for the Nomen-clature of Lipids developed by the IUPAC-IUB Commission on Biochemical Nomenclature, as set forth in European J. Biochem., 2, 127 (1967). Many Glycolipids are derivatives of long-chain bases related to sphingosine, and the Rules provide a semisystematic nomenclature for these derivatives. The compound previously known as dihydrosphingosine (D-erj/Aro-2-aminoocta-decane-l,3-diol) is called sphinganine, and this name may be modified to indicate additional substituents, higher or lower homologs, or sites of unsaturation. The trivial name sphingosine is retained for 4-sphingenine, but the term phytosphingosine is replaced by 4Z>-hydroxysphinganine.

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  Dynamic Aspects of Cell Surface Organization

  Cell Surface Reviews

  • George Poste, Garth L. Nicolson(Authors)
  • 2013(Publication Date)
  • North Holland

    (Publisher)

  coli enterotoxin (Holmgren, 1973; Donta and Viner, 1974; Zenser and Metzger, 1974) can all be glycolipid in nature. The mammalian proteins interferon (Besançon and Ankel, 1974a; Besançon et al., 1976), mac-rophage migration inhibitory factory (Higgins et al., 1976) and thyrotropin (Mullin et al., 1976) can also recognise specific sequences in the carbohydrate moiety of Glycolipids. Bacterial Glycolipids, the lipopolysaccharides, are impor-tant in host phage interactions (Losick and Robbins, 1969) and gangliosides may act as receptors for Sendai virus (Haywood, 1974) and Rubella virus (Shortridge and Biddle, 1972). In addition, Glycolipids are also known to be important blood group antigens (Hakomori, 1970b, 1975b) and both Forssman antigen (Siddiqui and Hakomori, 1971; Gahmberg and Hakomori, 1975b) and Θ antigen in mouse lymphocytes (Esselman and Miller, 1974; Miller and Esselman, 1975) can be represented in the carbohydrate sequences of Glycolipids. It is clear from this brief survey that Glycolipids can no longer be considered unimportant compo-nents of the lipid bilayer. The field which has generated much of the current excitement about Glycolipids as possible membrane receptors is that of cholera toxin. Although some of the literature is only of direct relevance to work on the molecular basis of the disease, much is pertinent to those interested in the general significance of Glycolipids in membranes. Because it is the only example of protein-cell surface glycolipid interaction which has been extensively studied, the work will be reviewed in some detail. Inferences drawn from these studies will be discussed with respect to the possible significance of loss of certain Glycolipids in cells transformed by tumour viruses (sections 7.4 and 7.5).

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  Biomolecules from Natural Sources

  Advances and Applications

  • Vijai Kumar Gupta, Satyajit D. Sarker, Minaxi Sharma, Maria Elida Pirovani, Zeba Usmani, Chelliah Jayabaskaran, Vijai Kumar Gupta, Satyajit D. Sarker, Minaxi Sharma, Maria Elida Pirovani, Zeba Usmani, Chelliah Jayabaskaran(Authors)
  • 2022(Publication Date)
  • Wiley

    (Publisher)

  The most well-known Glycolipids are sophorolipids (Bogaert et al. 2007; Oliveira et al. 2015), mannosylerythritol lipids (Im et al. 2001), rhamnolipids and treha-lose lipids (Figure 1.1). The glycolipods that this chapter will focus on is a case study of trehalose lipids, also known as trehalolipids. The amphiphilic character triggers them to aggregate at liquid interfaces with different degrees of polarity and hydrogen bridges, giving them the ability to reduce surface- and interfacial-tension between solids, liquids and gases. Furthermore most biosurfactants exhibit characteristics such as tolerance to pH, tem-perature and ionic strength, biodegradability, low toxicity, detergency, emulsification, de-emulsification and foaming. There is considerable interest in potential applications, 1 Glycolipids From Biosynthesis to Biological Activity toward Therapeutic Application Maria H. Ribeiro, Eva Fahr, and Sara Lopes Research Institute for Medicines (iMed.ULisboa), Department of Pharmaceutical Sciences and Medicines, Faculty of Pharmacy, Universidade Lisboa, Lisbon, Portugal *Corresponding author: [email protected] Figure 1.1 The chemical structures of the most common Glycolipids. 1.1 Introduction 3 due to their environmental friendly character and sustainability (Geys et al. 2014; Makkar et al. 2011; Santos et al. 2016; Smyth et al. 2010). Nowadays the preservation of the Earth as a sustainable planet is one of humanities greatest concerns. In line with this concern about the environment, many industries are changing to a global viewpoint on the future of manufacturing. In fact, they have recognized the potential of living cells in the pre-treatment of raw materials, processing operations, product modifications, selec-tive waste management, energy recycling and conservation.

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  Carbohydrate Chemistry

  Volume 14 Part II

  • John F Kennedy(Author)
  • 2007(Publication Date)
  • Royal Society of Chemistry

    (Publisher)

  188 3 74 Carbohydrate Chemistry The principal Glycolipids from the membranes of somatic cells and gonidia of VoZvox carteri have been identified as sulphoquinovosyldiglyceride and mono- and di-D-galactosyldiglyceride. 189 In another green alga, Fritschiella tuberosa, the end of linear growth has been demonstrated to coincide with a reduction in the glycolipid content. 190 The reduction in glycolipid content continued during the stationary phase. An unusual neuraminosylglycolipid (29) has been isolated from the hepato- pancreas of the starfish Parira pectinifera. Some of the proposed linkages have not been definitively confirmed. lgl Araf-(1 -t 3)-a-D-Galp-(l -+6)-p-D-Galp-(1+4)-Neu5Ac-(2 -t 3)-p-D-Galp-(l-4)-p-D-Glcp-(l -l)-Cer 3 f 1 Araf (29) A novel sphingophosphonoglycolipid has been isolated from the skin of the marine gastropod Aplysia kuroda.lg2 The lipid was a bis(2-aminoethylphos- phono)pentaosylceramide where the oligosaccharide contained one mole each of D-glucose, 3-O-methyl-~-galactose,and 2-amino-2-deoxy-D-galactose, and two moles of D-galactose. The D-mannolipid participating in the glycosyltransferase reaction of schistosome has been partially purified. 193 The lipid acceptor has several characteristics of a phosphorylated polyisoprenoid and appears to be synthesized by these parasites at relatively s!ow rates. K. R. Moseley and G . A. Thompson, jun., Plant Physiol., 1980, 65, 260. l9O M. Wettern, Phytochemhtry, 1980, 19, 513. 1 9 1 G. P. Smirnova and N. K. Kochetkov, Biochim. Biophys. Acta, 1980, 618, 486. 191 S. Araki, Y . Komai, and M. Satake, J. Biochem. (Jpn.), 1980, 87, 503. 193 F. D. Rumjanek, Comp. Biochem. Physiol., 1980,65, 345. 8 Chemical Synthesis and Modification of 01 ig osacchar i des, Pol ysacc harides, G I yco prote i n s, E nzymes, a nd G I yco I ipids C. M. STURGEON 1 Synthesis of Polysaccharides, Oligosaccharides, Glycoproteins, Glycopeptides, and Glycolipids Polysaccharides.

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  Organic Chemistry

  A Mechanistic Approach

  • Penny Chaloner(Author)
  • 2014(Publication Date)
  • CRC Press

    (Publisher)

  719 16.1 INTRODUCTION This chapter deals with two classes of natural products, lipids and carbohydrates; the chemis- try involved is applied carbonyl and alcohol chemistry. Although the molecules we will meet are often larger and appear more complex than those we discussed in previous chapters, what happens to them is essentially the same as with the simpler molecules. We will meet some new reagents, especially in carbohydrate chemistry, but the need for these mostly reflects a difference in the solubility of the substrates. Most organic molecules are soluble in organic solvents, but carbohydrates have limited solubility in organic solvents and are very soluble in water. However, the processes they undergo have not changed. 16.2 LIPIDS The term lipid technically means fat, but it is used to describe quite a wide range of related compounds, including fatty acids, steroids, prostaglandins, lipoproteins, sphingolipids, and phos- pholipids. Fatty acids and triglycerides are energy sources and used for energy storage as well as cell membrane construction. Steroids and prostaglandins fulfill many biological functions as chemical messengers. Some of these molecules, particularly the fatty acids, have a single polar “head group” and a long hydrocarbon “tail.” Despite the head group, they are generally more soluble in nonpolar than in polar media and have surfactant properties, explored in more detail in Section 16.2.1. They are sometimes called amphiphiles, as there is one part of the molecule, the head group, that is best solubilized in water and one part, the hydrocarbon tail, that is more com- patible with nonpolar solvents (Figure 16.1). This allows the formation of a range of structures including monolayers, bilayers, micelles, and vesicles, depending on the molecule, the solvent, and the concentration. 16.2.1 SURFACTANTS Figure 16.1 shows a typical surfactant molecule, with a polar head group and a nonpolar tail.

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  Advanced Nutrition

  Macronutrients, Micronutrients, and Metabolism, Second Edition

  • Carolyn D. Berdanier, Lynnette A. Berdanier(Authors)
  • 2015(Publication Date)
  • CRC Press

    (Publisher)

  Cholesterol esters B. Compound lipids: esters of fatty acids that contain substituent groups in addition to fatty acids and alcohol 1. Phospholipids: esters of fatty acids, alcohol, a phosphoric acid residue, and usually an amino alcohol, sugar, or other substituent 2. Glycolipids: esters of fatty acids that contain carbohydrates and nitrogen (but not phos-phoric acid). In addition to fatty acids and alcohol 3. Lipoproteins: loose combinations of lipids and proteins C. Derived lipids: substances derived by saponification from these groups Two other terms are frequently used in the classification of lipids but are not a division of the sys-tem just described. These are the neutral and polar lipids. Neutral lipids are uncharged lipids and include TGs, cholesterol, and cholesterol esters. Polar lipids have positive and negative charges on certain atoms of the molecule. Examples of these are the phospholipids that are the lipids in the cell membrane. Phosphatidylinositol (PIP), phosphatidylcholine, and phosphatidylethanolamine, for example, are membrane phospholipids and are polar. 262 Advanced Nutrition: Macronutrients, Micronutrients, and Metabolism STRUCTURE AND NOMENCLATURE S IMPLE L IPIDS Fatty Acids Fatty acids are carboxylic acids. They have a polar group (the carboxyl group) at one end and a methyl group at the other. A hydrocarbon chain is in the middle. Fatty acids can have a few car-bon atoms or more than 20; however, chain lengths of 16 and 18 carbons are the most prevalent. There is usually an even number of carbon atoms (with no branching) in the chain. The chain may be saturated (containing no double bonds) or unsaturated (containing one or more double bonds). Monounsaturated acids have one double bond; polyunsaturated acids have two or more. The nomenclature of fatty acids is frequently confusing because the same fatty acid can have more than one name: its common (or trivial) name and its systematic name.

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  Carbohydrate Chemistry

  Volume 12

  • John F Kennedy, N R Williams(Authors)
  • 2007(Publication Date)
  • Royal Society of Chemistry

    (Publisher)

  The conclusion is drawn in terms of the relative roles of carbohydrate and lipid moieties of the glycosphingolipids in maintaining that association with erythrocyte membranes. A comparison has been made of the glycosphingolipids of human lympho- cyte~.~' Thymocytes and peripheral blood lymphocytes did not have the same distribution of the simpler lipids as tonsil lymphocytes and contained larger amounts of more complex glycosphingolipids. The peripheral blood lympho- cytes contained more bound sialic acid than did either tonsil lymphocytes or t hymocytes. A comparative study of the glycolipid composition of plasma membranes from two types of rat ascites hepatomas and normal rat liver has been 61 B. L. Slomiany and A. Slomiany, European J . Biochem., 1978, 85, 249. 6a M. Dejter-Juszynski, N. Harpaz, H. M. Flowers, and N. Sharon, European J. Biochem., 1978, 83, 363. P. Hanfland, European J. Biochem., 1978, 81, 161. P. Hanfland, R.-G. Kladetzky, and H. Egli, Chem. and Phys. Lipids, 1978, 22, 141. K. A. Karlsson and G. Larson, F.E.B.S. Letters, 1978, 87, 283. 66 5. KoScielak, W. Mailinski, J. Zielehski, E. Zdebska, T. Brudzynski, H. Miller-Podraza, and B. Cedergren, Biochim. Biophys. Acta, 1978, 530, 385. 87 K. E. Stein and D. M. Marcus, Biochemistry, 1977, 16, 5285. Glycolipids and Gangliosides 493 reported.68 Normal liver membranes contained ceramide monohexose (CMH), ceramide dihexoside (CDH), and haematoside (GM~). Island-type hepatoma membranes contained ceramide trihexoside (CTH) and globoside as well as CMH, CDH, and G M ~ , whereas free-type hepatoma membranes were charac- terized by the presence of asialogangliosides but not Gaa3. A blood-group H-active fucolipid was a major component of free-type hepatoma membranes. It was noted that an increase in the glycolipid concentration was accompanied by a decrease in cell adhesiveness.

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