Carbohydrate-sulfotransferases chondroitin 6-sulfotransferase

Sulfation of the carbohydrate chain occurs after the monosaccharide to be sulfated has been incorporated into the growing carbohydrate j chain. The source of the sulfate is 3 -phosphoadenosyl-5 -phospho-sulfate (PAPS, a molecule of AMP with a sulfate group attached to the 5-phosphate). Sulfotransferases cause the sulfation of the carbohydrate chain at specific sites. [Note An example of the synthesis of a sulfated glycosaminoglycan, chondroitin sulfate, is shown in Figure 14.11.] PAPS is also the sulfur donor in glycosphingolipid synthesis. [Note A defect in the sulfation process results in one of several autosomal recessive disorders that affect the proper development and maintenance of the skeletal system. This illustrates Ihe importance of the sulfation step.]... 

Whereas the problem of the biosynthesis of the carbohydrate skeleton of dermatan sulfate is still entirely in the realm of speculation, some concrete information exists concerning the sulfation of this polysaccharide. Despite the fact that the sulfate group is located in the C-4 position of the galactosamine residue in both dermatan sulfate and chondroitin 4-aulfate, different suifotransferases seem to be responsible for the sulfar tion of these compounds. Davidson and Riley (1960) purified partially a sulfotransferase from extracts of rabbit skin which exhibited acceptor specificity for dermatan (desulfated dermatan sulfate). On a quantitative... 

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