Metabolism of Deoxyribonucleotides. Purification and Properties of Deoxyguanosine Monophosphokinase of Calf Thymus

An enzyme which catalyzes transphosphorylation between ATP and dGMP was purified about 1000-fold from calf thymus. ATP and dATP were the only phosphate donors and GMP and dGMP were the only phosphate acceptors in the reaction catalyzed by the purified preparation which was free from nucleoside diphosphokinase activity. Evidence suggesting that dGMP and GMP kinase activities are associated with a single enzyme protein is presented. These two kinase activities were remarkably activated by monovalent alkali metal ions, especially by the potassium ion. Several other properties of the purified enzyme are also described.