McDonnell Ursula, Hicks Matthew R, Hannon Michael J, Rodger Alison
Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK.
J Inorg Biochem. 2008 Dec;102(12):2052-9. doi: 10.1016/j.jinorgbio.2008.06.006. Epub 2008 Jun 20.
The interaction of enantiomerically pure dinuclear complexes of the form [Ru2(L-L)4L1]4+ (where L-L = 2,2'-bipyridine (bpy) or 1,10-phenanthroline (phen) and L1 = bis(pyridylimine) ligand ((C5H4N)CN(C6H4))2CH2)) with ct-DNA have been investigated by absorbance, circular dichroism, fluorescence displacement assays, thermal analysis, linear dichroism and gel electrophoresis. The complexes all bind more strongly to DNA than ethidium bromide, stabilise DNA and have a significant bending effect on DNA. The data for Delta,Delta-[Ru2(bpy)4L1]4+ are consistent with it binding to DNA outside the grooves wrapping the DNA about it. By way of contrast the other complexes are groove-binders. The phen complexes provide a chemically and enantiomerically stable alternative to the DNA-coiling di-iron triple-helical cylinder previously studied. In contrast to the di-iron helicates, the phen complexes show DNA sequence effects with Delta,Delta-[Ru2(phen)4L1]4+ binding preferentially to GC and Lambda,Lambda-[Ru2(phen)4L1]4+ to AT.
通过吸光度、圆二色性、荧光位移测定、热分析、线性二色性和凝胶电泳等方法，研究了[Ru2(L-L)4L1]4+形式的对映体纯双核配合物（其中L-L = 2,2'-联吡啶（bpy）或1,10-菲咯啉（phen），L1 = 双（吡啶基亚胺）配体((C5H4N)CN(C6H4))2CH2））与ct-DNA的相互作用。这些配合物与DNA的结合均比溴化乙锭更强，能使DNA稳定，并对DNA产生显著的弯曲作用。Δ,Δ-[Ru2(bpy)4L1]4+的数据表明其在沟槽外部与DNA结合并围绕DNA缠绕。相比之下，其他配合物是沟槽结合剂。phen配合物为先前研究的DNA盘绕双铁三螺旋圆柱体提供了一种化学和对映体稳定的替代物。与双铁螺旋配合物不同，phen配合物表现出DNA序列效应，Δ,Δ-[Ru2(phen)4L1]4+优先结合GC，Λ,Λ-[Ru2(phen)4L1]4+优先结合AT。
