Enzymatic phosphorylation of adenosine and 2,6-diaminopurine riboside.

Knowledge concerning the nature of the biologic synthesis of purine or pyrimidine mononucleotides is relatively limited. A significant contribution was the demonstration by Ostern and coworkers (3) of the phosphorylation of adenosine to adenosine-5’-phosphate (A-5’-P) and adenosinetriphosphate (ATP) by means of crude yeast extracts. The energy source for this reaction was supplied by the fermentation of hexose diphosphate or phosphoglyceric acid. These extracts did not act on guanosine or ribose and failed to form yeast adenylic acid. Recently, Sable (4) observed the disappearance of ATP in the presence of crude yeast fractions and adenosine. He suggested the direct phosphorylation of adenosine by ATP and the name adenosine phosphokinase for this enzyme. In order to provide some definitive information on the mechanism of conversion of adenosine to adenosine-5’-phosphate, we have purified this activity from yeast autolysates. An enzyme preparation has been obtained which catalyzes the reaction