Triple helical di-iron complexes, readily prepared through interaction of iron(II) ions with imine-based ligands, are cylinder-shaped tetracations comparable in size and shape to common protein DNA recognition units. They have a strong tendency to coil DNA, and have recently been found to induce formation of three-way junctions in palindromic oligonucleotides. To introduce potential H bond acceptor units onto the surface of triple-helicates, new iron(II) complexes have been synthesized in which the central linking unit in the bridging ligand is S or O, instead of CH2. The DNA binding properties of these new metallo-helicates were studied using UV-vis spectroscopy and circular and linear dichroism. Results show that the three iron triple helicates bind the DNA in a similar way but that the stability of the triple helicate unit is decreased with the O linked bridging ligand.
三螺旋二
铁配合物很容易通过
铁 (II) 离子与
亚胺基
配体的相互作用制备,是圆柱形四联体,其大小和形状与常见的蛋白质 DNA 识别单元相当。它们具有强烈的卷绕 DNA 的倾向,最近发现它们可以诱导回文寡核苷酸中三路连接的形成。为了将潜在的H键受体单元引入到三螺旋表面,合成了新的
铁(II)配合物,其中桥连
配体的中心连接单元是S或O,而不是
CH2。使用紫外-可见光谱以及圆和线性二色性研究了这些新型
金属螺旋物的 DNA 结合特性。结果表明,三个
铁三螺旋以类似的方式结合 DNA,但三螺旋单元的稳定性随着 O 连接桥
配体而降低。