Glycosaminoglycans classes

Being an alternating copolymer of ahexosamine and an alduronic acid, heparin belongs to the class of glycosaminoglycans (GAG), formerly... 

Brand Name(s) Hep-Lock, Hep-Pak CVC Chemical Class Glycosaminoglycan, sulfated... 

Chemical Class Glycosaminoglycan, sulfated heparin derivative Clinical Pharmacology ... 

The six major classes of glycosaminoglycans are divided according to monomeric composition, type of glycosidic linkages, and degree and location of sulfate units. The structure of the glycosaminoglycans and their distribution in the body is illustrated in Figure 14.4. 

Six major classes of glycosaminoglycans There are six major classes of glycosaminoglycans. These include chondroitin 4- and 6-sulfates, keratan sulfate, dermatan sulfate, heparin, heparan sulfate, and hyaluronic acid. 

Infrared spectra of glycosaminoglycans in D20 and DC1 were used165 for quantitative evaluation of the uronic acid and acetamido groups in this class of polysaccharide. The results showed that i.r. spectroscopy of compounds in D20 solution provides a simple, quantitative basis for examination of ras(COJ) and amide I bands in heparin and chondroitin 4-sulfate. In DC1, analysis was based on p(C02H) and amide I bands which were well resolved. The apparent acid-dissociation constants of the studied polysaccharides were estimated from the absorbance of p(C02) or p(C02H) bands, or both, at different pH (pD) values. 

Glycosaminoglycans (GAGs) are unbranched chains having repeating disaccharide units, which, with the exception of keratan sulfate, contain an acid and a base. The KS disaccharide unit consists of a hexose and a base. The structures of the different classes of GAG disaccharide units are given in Fig. 1, and summarized in Table I. 

The sulfeted mucopolysaccharides or SMPS represent a large class of dmgs which are currently sold under various commercial names. SMPS are non-characterized glycosaminoglycans vdiich contain dermatan, heparan, chondroitin sulfate and other non-chaiacterized glycosaminoglycans. While the composition of these agents does not differ markedly, each product is marketed for a specific indication. The mechanism of action and... 

Six classes of glycosaminoglycans have been described. All are heteropolysaccharides and contain repeating disaccharide units. The compositions and structures of the repeating disaccharide units are shown in Table 11-2 and Figure 11-7. In five glycosaminoglycans, the... 

Fig. 2. Summary of structural features of C-type animal lectins. The (nearly) invariant residues found in the coimnon carbohydrate-recognition domain of the C-type lectins are shown, flanked by schematic diagrams of the special effector domains (if any) found in individual members of the family. GAG, glycosaminoglycan EGF, epidermal growth factor. Reproduced from K. Drickamer, Two Distinct Classes of Car bohydrate-recognition Domains in Animal Lectins, J. Biol. Chem., 263 (1988) 9557-9560 (Ref. 35) 1988. The American SocietyforBiochemistry Molecular Biology with permission by Professor Kurt Drickamer and The American Society for Biochemistry Molecular Biology.

D-Xylose is unusual as a structural component in mammalian cells. It is only present as the linker between protein and carbohydrate in proteoglycans, a class of extracellular macromolecules composed of glycosaminoglycan (GAG) chains attached to a core protein. Biosynthesis of GAG chains starts with the formation of a glycosidic bond between a serine residue of the protein and the unique o-xylose of the GAG chain. Then a specific linker tetrasaccharide is synthesized and is used as the acceptor for the elongation of GAG chains (Fig. 8). 

The glycosaminoglycans are distinguished from the oligosaccharide structures found in all other classes of glycoproteins (with the exception of those that contain poly-... 

Glycosaminoglycans found in connective tissues are divided in five main classes [3], Their chemical structures are given in Figure 1. 

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