ENZYMATIC-SYNTHESIS OF URIDINE-5'-O-(2-THIODIPHOSPHOGLUCOSE) AND RELATED SUGAR PHOSPHOROTHIOATES
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
Methods have been developed for the enzymatic synthesis of -glucose 1-thiophosphate, -galactose 1-thiophosphate, glucose 6-thiophosphate, uridine-5-O-(2-thiodiphosphoglucose), and uridine-5-O-(2-thiodiphosphogalactose). The purified compounds were shown to be substrates for sucrose phosphorylase, glactokinase, UDP-glucose pyrophosphorylase, galactose-1-phosphate uridyltransferase, hexokinase, glucose-6-phosphate dehydrogenase, UDP-glucose dehydrogenase, and UDP-galactose-4-epimerase. The formation of uridine-5-O-(2-thiodiphosphoglucose) from -glucose 1-thiophosphate and UTP as catalyzed by UDP-glucose pyrophosphorylase produces only one of the two possible epimers at the -thiophosphoryl position. The absolute stereochemistry has not been determined. Uridine-5-O-(2-thiodiphosphoglucose) was not utilized as an alternate substrate in the transfer of a glucosyl group in the reactions catalyzed by glycogen synthetase and sucrose synthetase. The incubation of cyanate and thiophosphate at pH 5.0 was found to result in the rapid removal of sulfur from the thiphosphate. The reaction is stoichiometric with respect to cyanate and thiophosphate. The data are consistent with the rapid formation and hydrolysis of thiocarbamoyl phosphate. 1988.
