Heparan sulfate tissues

Fig. 34.—Circular Dichroism of Glycosaminoglycans (a) Hyaluronic Acid (b) Heparan Sulfate from Normal Mammalian Tissue (c) Chondroitin 4-Sulfate (d) Dermatan Sulfate ...

Hurler syndrome (MPS type I) is caused by deficiency of a-iduronidase, a lysosomal enzyme involved In degradation of dermatan sulfate and heparan sulfate, which accumulate in the cells of all tissues and spill over into the urine. 

Subsequent modifications of the polymers involve extensive formation of O-sulfate esters,1903 193 197 N-deacetylation and N-sulfation,198/199 and epimerization at C5.10 In some tissues almost all GluA is epimer-ized.200 The modifications are especially extensive in dermatan, heparan sulfates, and heparin (see also p. 177).196 201 203b The modifications are not random and follow a defined order. N-Deacetylation must precede N-sulfation, and O-sulfation is initiated only after N-sulfation of the entire chain is complete. The modifications occur within the Golgi (see Fig. 20-7) but not all... 

Most of the polysaccharides of interest in this text are termed glycosaminoglycans, polymers that contain an amino sugar in the repeat unit. Glycosaminoglycans that are abundant in mammalian tissues include hyaluronan, chondroitin sulfate, dermatan sulfate, keratan sulfate, and heparin-heparan sulfate (see Table 2.4). Most of these glycosaminoglycans,... 

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