Hokkaido University, Sapporo, Japan.
DNA Repair (Amst). 2009 Oct 2;8(10):1250-4. doi: 10.1016/j.dnarep.2009.07.011. Epub 2009 Aug 21.
The human NUDT5 protein catalyzes the hydrolysis of 8-hydroxy-dGDP. To examine its substrate specificity, four oxidized deoxyribonucleotides (2-hydroxy-dADP, 8-hydroxy-dADP, 5-formyl-dUDP, and 5-hydroxy-dCDP) were incubated with the NUDT5 protein. Interestingly, all of the nucleotides, except for 5-hydroxy-dCDP, were hydrolyzed with various efficiencies. The kinetic parameters indicated that 8-hydroxy-dADP was hydrolyzed as efficiently as 8-hydroxy-dGDP. The hydrolyzing activities for their triphosphate counterparts were quite weak. These results suggest that the NUDT5 protein eliminates various oxidized deoxyribonucleoside diphosphates from the nucleotide pool and prevents their toxic effects.
人源 NUDT5 蛋白可催化 8-羟基-dGDP 的水解。为了研究其底物特异性，将四种氧化型脱氧核苷酸（2-羟基-dADP、8-羟基-dADP、5-甲酰基-dUDP 和 5-羟基-dCDP）与 NUDT5 蛋白孵育。有趣的是，除了 5-羟基-dCDP 之外，所有核苷酸均以不同的效率被水解。动力学参数表明，8-羟基-dADP 的水解效率与 8-羟基-dGDP 相当。其三磷酸酯对应物的水解活性则相当弱。这些结果表明，NUDT5 蛋白可从核苷酸池中清除各种氧化型脱氧核苷二磷酸，并防止其产生毒性作用。
