The interaction of salphen-type NiII, CuII and ZnII complexes with native DNA was investigated by exploiting linear dichroism experiments. The NiII complex behaves as a typical intercalator, binding strongly and stiffening and unwinding the DNA. The strength of the DNA interaction is slightly weaker for the copper complex and much weaker for the zinc complex. Plasmid-DNA gel electrophoresis experiments indicated that while CuII and ZnII complexes do not induce the unwinding of supercoiled DNA, the NiII complex has a nuclease activity without the addition of external agents. On the other hand, as shown in the PCR assays, we demonstrate that, at the used concentrations, only the CuII complex is able to inhibit the DNA amplification mediated by Taq DNA polymerase. In this paper we have also reported a detailed characterization of the three compounds including 2D-NMR and ESI-mass experiments and X-ray single crystal structure of the copper and nickel compounds.
通过线性二色性实验研究了 Salphen 型 NiII、CuII 和 ZnII 配合物与天然 DNA 的相互作用。 NiII 复合物表现为典型的嵌入剂,强烈结合并使 DNA 硬化和解旋。
铜络合物的 DNA 相互作用强度稍弱,而
锌络合物的 DNA 相互作用强度则弱得多。质粒-DNA凝胶电泳实验表明,虽然CuII和ZnII复合物不会诱导超螺旋DNA解旋,但NiII复合物在不添加外部试剂的情况下具有
核酸酶活性。另一方面,如 PCR 测定所示,我们证明,在所使用的浓度下,只有 CuII 复合物能够抑制 Taq
DNA 聚合酶介导的 DNA 扩增。在本文中,我们还报道了这三种化合物的详细表征,包括
铜和
镍化合物的 2D-NMR 和 ESI 质量实验以及 X 射线单晶结构。