§Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland.
‡Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Wintherthurerstrasse 190, 8057 Zürich, Switzerland.
J Am Chem Soc. 2015 Apr 15;137(14):4728-34. doi: 10.1021/ja512547g. Epub 2015 Apr 6.
Human DNA polymerase η (hPol η) contributes to anticancer drug resistance by catalyzing the replicative bypass of DNA adducts formed by the widely used chemotherapeutic agent cis-diamminedichloroplatinum (cisplatin). A chemical basis for overcoming bypass-associated resistance requires greater knowledge of how small molecules influence the hPol η-catalyzed bypass of DNA adducts. In this study, we demonstrated how synthetic nucleoside triphosphates act as hPol η substrates and characterized their influence on hPol η-mediated DNA synthesis over unmodified and platinated DNA. The single nucleotide incorporation efficiency of the altered nucleotides varied by more than 10-fold and the higher incorporation rates appeared to be attributable to the presence of an additional hydrogen bond between incoming dNTP and templating base. Finally, full-length DNA synthesis in the presence of increasing concentrations of synthetic nucleotides reduced the amount of DNA product independent of the template, representing the first example of hPol η inhibition in the presence of a platinated DNA template.
人类 DNA 聚合酶 η（hPol η）通过催化由广泛使用的化疗药物顺式二氨二氯铂（顺铂）形成的 DNA 加合物的复制旁路，有助于抗癌药物耐药性。克服旁路相关耐药性的化学基础需要更多地了解小分子如何影响 hPol η 催化的 DNA 加合物旁路。在这项研究中，我们展示了合成核苷三磷酸如何作为 hPol η 底物起作用，并描述了它们对 hPol η 介导的未修饰和铂化 DNA 上 DNA 合成的影响。改变核苷酸的单核苷酸掺入效率变化超过 10 倍，并且较高的掺入速率似乎归因于进入的 dNTP 和模板碱基之间存在额外的氢键。最后，在合成核苷酸浓度增加的情况下进行全长 DNA 合成，与模板无关地减少了 DNA 产物的量，这代表在存在铂化 DNA 模板的情况下 hPol η 抑制的第一个例子。
