Stereochemical course of a phosphokinase using a chiral [18O]phosphorothioate. Comparison with the transfer of a chiral [16O,17O,18O] phosphoryl group

Abstract
Synthetic adenosine 5''-O-[3-18O,3-thio]triphosphate having the R configuration at the .gamma.-P was used as a substrate in the reaction catalyzed by [Escherichia coli] glycerol kinase. The product sn-glycerol 3-[18O]phosphorothioate was isolated, and the configuration at P was determined by ring closure to the 2 diastereoisomeric cyclic 2,3-phosphorothioates of sn-glycerol and analysis of the 18O content of each diastereoisomer. The structural identity of these diastereoisomers was determined by correlation with 1 of the corresponding diastereoisomers of the cyclic 2,3-phosphorothioate of D-glycerate, whose crystal structure is reported here. Apparently, glycerol kinase catalyzes the transfer of a thiophosphoryl group with inversion of the configuration at P, in gratifying agreement with the result from the transfer of a chiral [16O,17O,18O]phosphoryl group.