Adenosine 5 -phosphate pyrophosphorylase

This enzyme [EC 2.7.7.28], also known as NDP-hexose pyrophosphorylase, catalyzes the reaction of a nucleoside triphosphate with a hexose 1-phosphate to produce a NDP-hexose and pyrophosphate (or, diphosphate). In the reverse reaction the NDP-hexose can be, in decreasing order of activity, guanosine, inosine, and adenosine diphosphate hexoses in which the sugar is either glucose or mannose. 

Several cases have been documented in which a different, naturally occurring, glycosyl phosphate substitutes for the true substrate of the pyrophosphorylase. Adenosine 5 -(a-D-xylopyranosyl pyrophosphate) was prepared by the action of the pyrophosphorylase of adenosine 5 -(a-D-glucopyranosyl pyrophosphate) from wheat flour,218... 

F2. Flaks, J. G., Erwin, M. J., and Buchaium, J. M., Biosynthesis of the purines— the synthesis of adenosine 5 phosphate and 5-amino-4-imidazolecarboxamide ribotide by a nucleotide pyrophosphorylase. J. Biol. Chem. 288, 201 (1957). 

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