Ribitol, phospho

Alkaline hydrolysis of the teichoic acid gave a mixture of monophosphates of 0-D-glucosyl-D-ribitol (XVII), only traces of diphosphates, and no phos-pho diesters. Removal of D-glucose by 8-D-glucosidase gave ribitol 1-phosphate and ribitol 2-phosphate (and no ribitol 3-phosphate). Thus, the phospho diester linkages are at positions 1 and 5 in the polymer. 

Fig. 9. HPLC patterns of a mixture of ethylene glycol (Cj), glycerol (C,), erythritol (C4), and ribitol (C5) (upper), and NaI04/NaBH4/phosphatase-treated 5-phospho( C]ribosyl pentapeptide...

Strong support for the existence of the postulated six-carbon carboxy-lated intermediate was the finding that a structural analog of the intermediate, 2-carboxy-D-ribitol 1,5-P2, is a potent inhibitor of the enzyme. Furthermore, the proposed intermediate, 2-carboxy-3-ketoribitol 1,5-Pj, has been synthesized and is a substrate for the carboxylase. An interesting observation is that 2-carboxy-3-ketoribitol 1,5-P2 also hydrolyzes spontaneously (in the presence of platinum oxide) to yield 3-phospho-glycerate. In contrast to the enzyme-catalyzed carboxylation of ribulose-... 

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