Chondroitin 4-sulfate chain, biosynthesis

Early studies of the turnover of the chondroitin sulfate protein complex of rat costal cartilage (Gross ei al., I960) show-ed that the carbohydrate and protein moieties were metabolized at the same rate. Similarly, Campo and Dziewiatkowski (1962) found that the formation of both moieties proceeded in a roughly parallel fashion in cartilage preparations incubated in vitro. However, these experiments did not permit any conclusions as to the order in which the tw O components were synthesized. The investigations of the eell-frcc biosynthesis of the protein polysaccharide, reviewed above, have indicated that the synthesis of the protein core, or at least part of it, precedes the formation of the chondroitin sulfate chains and... 

Examples of the use of induced biosynthetic effects for the deduction of the processes involved include the use of puromycin and cyclohexi-mide. These compounds, according to experiments with other systems, inhibit protein synthesis. Thus the inhibition of biosynthesis of hyaluronic acid and dermatan sulfate in human fibroblast cultures (M13, M16), of hyaluronic acid in synovial cells (S31), and of chondroitin sulfate (HI) led to the conclusion that the synthesis of protein acceptor is necessary for the polysaccharide chain initiation. Comparison of the effects of 1-butanol on the biosynthesis of chick cartilage chondroitin sulfate and streptococcal hyaluronic acid led to the suggestion that binding of Mg + ions and the uridine diphosphate moiety results in stabilization of the spatial arrangement of the specific enzymes (S47, T4). 

D17. DeLuca, S., Richmond, M. E., and Silbert, J. E., Biosynthesis of chondroitin sulfate. Sulfation of the polysaccharide chain. Biochemistry 12, 3911-3915... 

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