Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA.
Chem Res Toxicol. 2012 Aug 20;25(8):1568-70. doi: 10.1021/tx300289d. Epub 2012 Jul 23.
We used surface plasmon resonance (SPR) to characterize the binding interactions between the exonulease-free Klenow fragment (Kf-exo(-)) and unmodified and modified dG adducts derived from arylamine carcinogens: fluorinated 2-aminofluorene (FAF), 2-acetylaminofluorene (FAAF), and 4-aminobiphenyl (FABP). Tight polymerase binding was detected with unmodified dG and the correct dCTP. The discrimination of correct versus incorrect nucleotides was pronounced with K(D) values in the order of dCTP ≪ dTTP < dATP < dGTP. In contrast, minimal selectivity was observed for the modified templates with Kf-exo(-) binding tighter to the FAAF (k(off): 0.02 s(-1)) and FABP (k(off): 0.01 s(-1)) lesions than to FAF (k(off): 0.04 s(-1)).
我们使用表面等离子体共振（SPR）来描述无核酸外切酶的 Klenow 片段（Kf-exo(-)）与未修饰和修饰的 dG 加合物之间的结合相互作用，这些加合物来源于芳基胺类致癌物质：氟化 2-氨基芴（FAF）、2-乙酰氨基芴（FAAF）和 4-氨基联苯（FABP）。与未修饰的 dG 和正确的 dCTP 检测到紧密的聚合酶结合。用 K(D)值检测正确与不正确核苷酸的区分非常明显，顺序为 dCTP<dTTP<dATP<dGTP。相比之下，对于修饰模板，Kf-exo(-)的结合表现出最小的选择性，对于 FAAF（k(off): 0.02 s(-1)）和 FABP（k(off): 0.01 s(-1)）损伤的结合比 FAF（k(off): 0.04 s(-1)）更紧密。
