Keratan

Fig. 33.—A stereo view of the 2-fold helix of keratan 6-sulfate (39) stabilized by intrachain hydrogen-bonds. The sulfate groups are located on the periphery of the sinuous chain.

Keratan 6-sulfate, 383-384,427 Ketals, nomenclature, 123-124 Ketoaldonic acids, 51,106-107 Ketoaldoses, 51,79-80 Ketoses... 

The biological significance of chitosan biomaterials in the hiunan body depends largely on the actions that certain hydrolases exert on them. The resulting chitoohgomers stimulate various cells, while the released monomers are phosphorylated and incorporated into hyaluronan, keratan sulphate and chondroitin sulphate, components of the intracellular matrix and connective tissue [348]. 

As shown in Figure 48-8, the keratan sulfates consist of repeating Gal-GlcNAc disaccharide units containing sulfate attached to the 6 position of GlcNAc or occasionally of Gal. Type 1 is abundant in cornea, and type II is found along with chondroitin sulfate attached to hyaluronic acid in loose connective tissue. Types I and II have different attachments to protein (Figure 48—8). 

MIM 252940) Morquio A MPS IVA 6-sulfatase Galactosamine 6-sulfatase Keratan sulfate, chondroitin 6-sulfate... 

ECM, extracellular matrix HA, hyaluronic acid CS, chondroitin sulfate KS I, keratan sulfate I DS, dermatan sulfate HS, heparan sulfate. 

In various types of arthritis, proteoglycans may act as autoantigens, thus contributing to the pathologic feamres of these conditions. The amount of chondroitin sulfate in cartilage diminishes with age, whereas the amounts of keratan sulfate and hyaluronic acid increase. These changes may contribute to the development of osteoarthritis. Changes in the amounts of cer-... 

The major GAGs are hyaluronic acid, chondroitin 4- and 6-sulfates, keratan sulfates I and II, heparin, heparan sulfate, and dermatan sulfate. 

GM1-gangliosidosis, Morquio B GM1-ganglioside galactose-rich fragments of glycoproteins GM1 ganglioside Keratan sulfate... 

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