The stereochemical course of the reaction catalyzed by creatine kinase.

Adenosine [gamma-(S)-16O, 17O, 18O]triphosphate has been used as a substrate in the reaction catalyzed by creatine kinase, and the configuration at phosphorus in the product [16O, 17O, 18O]phosphocreatine has been determined. The reaction proceeds with inversion of the configuration, consistent with the emerging pattern of behavior among the phosphokinases. This result, coupled with recently published data from NMR, ESR, and infrared studies of ternary and quaternary complexes od creatine kinase with its substrates and inhibitors, defines the enzyme-catalyzed transphosphorylation as an associative in-line transfer of the phosphoryl group between the bound substrates.