Phosphate-transfer reactions of adenosine and inosine nucleotides.

but purified adenylate kinase of muscle tissue does not catalyse reaction (2). It is possible that the enzyme is identical with the adenylate kinase of other tissues, which, according to Kotelnikova (1949, 1950) and Barkulis & Lehninger (1951), differs from the muscle-adenylate kinase. It is also possible that the transfer is the result of the combined action of reactions (3) and (1). In this case catalytic quantities of ADP and ATP would participate in the reaction. No detectable quantities of these reagents were present at the beginning of the incubation period, but this does not rule out the presence of catalytic amounts.