소 간 mitochondrial deoxyguanosine kinase 활성은 purine 및 pyrimidine nucleoside triphosphate에 의하여 조절되었다. 생리적인 pH(7.4)에서 효소는 deoxythymidine triphosphate와 uridine triphosphate와 같은 pyrimidine triphosphate를 purine nucleoside triphosphate 보다 더욱 기질로 잘 이용하였다. 효소반응의 distal end product인 deoxyguanosine triphosphate와 deoxyinosine triphosphate는 인산공여체로 전혀 작용하지 않았다. Pyrimidine nucleoside triphosphate는 pH7.4에서 효소활성을 증가시켰으나 효소반응의 최적 pH인 5.5에서는 효소활성을 저해하였다. Nucleoside mono- 및 diphosphate에서는 deoxyguanosine kinase 작용의 생성물인 deoxyguanosine monophosphate, deoxyinosine monophosphate, deoxythymidine diphosphate 및 uridine diphosphate가 효소활성을 저해하였다. Nucleoside triphosphate의 경우에는 deoxyinosine triphosphate 및 deoxyguanosine triphosphate가 효소활성을 강하게 저해했으나, guanosme triphosphate와 deoxyadenosine triphosphate는 약하게 저해하였다. Uridine triphosphate와 deoxythymidine triphosphate는 효소활성을 증가하였다. Pyrimidine triphosphate에 의한 효소활성의 증가는 deoxyguanosine triphosphate의 첨가에 의하여 상쇄되었다.
The enzymatic activity of mitochondrial deoxyguanosine (dGuo) kinase from bovine liver was controlled by purine and pyrimidine nucleoside triphosphates. At physiological pH (7.4), the enzyme utilized pyrimidine nucleoside triphosphates such as deoxythymidine triphosphate (dTTP) and uridine triphosphate (UTP) better than purine nucleoside triphosphates. The distal end products of the enzyme reaction, deoxyguanosine triphosphate (dGTP) and deoxyinosine triphosphate (dITP), showed no activity as phosphate donors. Pyrimidine nucleoside triphosphates such as dTTP and UTP increased the enzyme activity at pH 7.4, but decreased it at optimum pH (5.5) of the reaction. Among nucleotides mono-and diphosphates tested, only products of the dGuo kinase reaction, deoxyguanosine monophosphate (dGMP), deoxyinosine monophosphate (dIMP), deoxythymidine diphosphate (dTDP) and uridine diphosphate (UDP) caused inhibition of the enzyme. In the case of nucleoside triphosphates, dGTP and dITP produced the strongest inhibition. Purine nucleotides such as guanosine triphosphate (GTP) and deoxyadenosine triphosphate (dATP) also caused considerable inhibition. On the other hand, pyrimidine nucleotides (dTTP, UTP) apparantly increased the enzyme activity. Activation by pyrimidine nucleoside triphosphate can be reversed by the addition of dGTP, and, conversely, inhibition by dGTP can be overcome by addition of dTTP.
