glycolipid


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Glycolipid

One of a class of compounds having solubility properties of a lipid and containing one or more molecules of a covalently attached sugar.

Glycosphingolipids, the most abundant and structurally diverse type of glycolipids in animals, are glycosides of ceramide, a fatty acid amide of the amino alcohol sphingosine. Galactosyl ceramide is enriched in brain tissue and is a major component of the myelin sheaths around nerves. Glucosyl ceramide is present in the cell membranes of many cell types and is abundant in serum.

Larger, neutral glycosphingolipids containing more than one sugar include lactosyl ceramide, abundant in leukocyte membranes; globosides; and other oligosaccharyl ceramides, some of which are important antigens defining blood groups. Gangliosides are oligosaccharyl ceramides, abundant in brain, spleen, erythrocytes, liver, and kidney, that contain glucose, galactose, N-acetylglucosamine, and sialic acids.

Glycosphingolipids carry blood group antigens and define tumor-specific or developmental antigens. In addition, they serve as receptors for many microorganisms and toxins, as modulators of cell surface receptors that mediate cell growth, and as mediators of cell adhesion. See Antigen, Cellular adhesion

Glycosyl phosphatidylinositols are a class of glycolipids that serve as membrane anchors for a multitude of proteins in organisms ranging from yeast to protozoa to humans. Glycosyl phosphatidylinositol–core structures can have many different modifications, depending upon the protein and cell type. Lipophosphoglycans are glycosyl phosphatidylinositols attached to large polysaccharide structures that coat the surfaces of many parasitic protozoa, such as Leishmania donovani, the causative agent of visceral leishmaniasis (kala azar). Lipophosphoglycans appear to protect these organisms from host defenses.

Mannosylphosphoryl dolichol, glucosylphophoryl dolichol, and oligosaccharyl phosphoryl dolichols are glycolipids with sugars attached to large polyisoprenoids by phosphate esters. Dolichols are structurally related to cholesterol. Saccharylphosphoryl dolichols serve as important biosynthetic intermediates in the assembly of both asparagine-linked glycoproteins and glycosyl phosphatidylinositols. See Glycoprotein

Glycosyl glycerides are glycolipids that have a structure analogous to phospholipids. They are the major glycolipids of plants and microorganisms but are rare in animals.

Bacteria produce a wide variety of glycolipids not easily categorized. Examples include fatty acid esters of carbohydrates, such as cord factor. Cord factor is a toxic component of the waxy capsular material of virulent strains of Mycobacterium tuberculosis, the causative agent of tuberculosis. Mycosides, glycolipids that are also found in tubercle bacilli, comprise long-chain, highly branched, hydroxylated hydrocarbon terminated by a phenol group, with the sugar glycosidically attached to the phenolic hydroxyl. See Lipid, Sphingolipid, Tuberculosis

glycolipid

[¦glī·kō¦lip·əd]
(biochemistry)
Any of a class of complex lipids which contain carbohydrate residues.
References in periodicals archive ?
That particular carbohydrate was found to be a pentose sugar and the glycerol was absent in the lipid, hence this indicates that the isolated biosurfactant was a glycolipid.
Interestingly, insertion of VCC into the membrane bilayer did not cause any redistribution of the lipid raft components like cholesterol and glycolipids implying that raft association was not critical for pore-formation by VCC.
The different components of lipids, including total phospholipids, glycolipids and free fatty acids (FFA) were measured by standard procedures as described by Marinetti (1962), Raughan and Batt (1968) and Koniecko (1979), respectively, whereas total glycerides were indirectly calculated by subtracting all these from total lipid values.
We know that both the monoclonal antibody and the Glycolipid compound have a standalone therapeutic effect.
Nonetheless, the intralysosomal accumulation of one lipid (CTH) is likely to disrupt the flow of lipids in the endosome/lysosome pathway, leading to secondary disturbances of other glycolipids (14).
Researchers at the La Jolla Institute for Allergy & Immunology (LIAI), San Diego, have identified the bacteria, Sphingomonas, as containing a glycolipid which naturally triggers an immune response from the body's natural killer (NK) T cells.
Since all the Stx types recognize Gb3, effort has been made to develop a bacterial construct that could mimic as a glycolipid receptor and neutralize the toxin (19).
A glycolipid of hypervirulent tuberculosis strains that inhibits the innate immune response.
Specifically, the joint research group generated abnormal proteins in the GPI anchor, a group of proteins with glycolipid found in the cell.
Characterization of this putative neoepitope presumably specific for uPAR(II-III) is, however, further complicated by the fact that the linker region between domains I and II exhibits different conformations depending on the presence of the glycolipid anchor on uPAR (35).
This in turn causes the accumulation of certain detrimental lipids in the body, especially the glycolipid glucocerebroside.
Urinary oligosaccharide excretion in disorders of glycolipid, glycoprotein and glycogen metabolism.