Glycosaminoglycan family

The glycosaminoglycans family is composed of hyaluronic acid, chon-droitin sulphates, dermatan sulphate, heparan sulphate, heparin and keratan sulphate. They are present in diverse tissues, mainly as branches of very large proteoglycans, in which the core is constituted by proteins. Glycosaminoglycans are water-soluble or highly swollen. In this family, heparin itself constitutes a subfamily, as its composition and the resulting activities are diverse. For this reason, it may be more properly designated as heparins . 

In a short review Pomin has presented the results of structural studies of glycosaminoglycans families including chondroitin sulfate, dermatan, heparin, heparan sulfate, and hyaluronic acid. He has pointed out the pivotal contribution of NMR parameters, particularly scalar and residual dipolar couplings, to the progress in elucidation of the structural, dynamical, conformational and intermolecular binding aspects of the carbohydrates. 

Another serine protease inhibitor of the al-antitrypsin family (serpin) is heparin cofactor II (HCII), which also forms a 1 1 complex with thrombin, but does not react with factor Xa [4,10]. The rate of inhibition of thrombin is not only increased by heparinoids but also by the related glycosaminoglycan dermatan sulfate. The identification of an inhibitor variant and site-directed mutagenesis studies on HC II cDNA led to the understanding that the binding sites for heparin and dermatan sulfate may be overlapping but not identical. Further proteinase inhibitors interacting with heparinoids are tissue factor pathway inhibitor and protease nexin-1. 

N-Acetylneuraminic acid N-Acetylneuraminic acid (NANA) is a member of the family of sialic acids, each of which is acylated at a different site. These compounds are usually found as terminal carbohydrate residues of oligosaccharide side chains of glycoproteins, glycolipids, or, less frequently, of glycosaminoglycans. The]... 

Robinson MJ, Tessier P, Poulsom R, Hogg N. 2002. The S100 family heterodimer, MRP-8/14, binds with high affinity to heparin and heparan sulfate glycosaminoglycans on endothelial cells. J Biol Chem 277(5) 3658—3665. 

Proteoglycans are major components of the extracellular matrix in animal cells. They are composed of core proteins and glycosaminoglycan polysaccharides. Heparin and heparan sulfate are the most complex glycosaminoglycans, a family of molecules that also includes chon-... 

HSV-1 vims entry is mediated by multiple glycoproteins present in the envelope and is a rather complex process. Initial adhesion to the cellular membrane is mediated by the interaction of gC and gB with glycosaminoglycan heparan sulfate. Subsequently, gD binds to a specific cellular receptor, either a member of the TNF receptor family [herpes vims entry mediator A (HveA)], immunoglobulin superfamily (HveB, HveC), or 3-O-sulfated heparan sulfate. Then, the vims enters the cell through membrane fusion promoted by the gH/gL complex and gB (117). 

Interestingly, the secretion of FGF family members that mediate tissue repair resembles IL-1 secretion, that is, not involving the Golgi. The FGF family proteins also bind to their receptors by P-barrel structures that interact with a glycan (in this case known to be heparin) during activation. Hyaluronan and heparin are glycosaminoglycans (Sect. 6.3.1). 

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