Abstract
A non-enzymic transphosphorylation between adenosine triphos-phate and orthophosphate was demonstrated. The reaction is catalyzed by bivalent metal ions. Of those tested, Mn++, Ca++ and Cd++ were found the most effective. The reaction has a sharp pH optimum. With Mn-- ions the rate of transphosphorylation is optimum at adenosine triphosphate/metal ratios between 0.6 and 1.0. A mechanism is proposed for the reaction, and its relation to enzymic transphosphorylation is discussed.