Interaction between the Heme and a G-Quartet in a Heme-DNA Complex
Interaction between the Heme and a G-Quartet in a Heme-DNA Complex
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DOI：
10.1021/ic3005739
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发表时间：
2012-08-06
影响因子：
4.6
通讯作者：
Yamamoto, Yasuhiko
中科院分区：
文献类型：
--
作者：
Saito, Kaori;Tai, Hulin;Yamamoto, Yasuhiko
用~ 1H NMR研究了血红素（Fe ~（3+））与由人端粒的一个重复序列形成的平行G-四链体DNA d（TTAGGG）的复合物的结构。因此，络合物中血红素（Fe 3+）的净+1电荷被G-四联体的八个羰基氧原子包围。配合物中血红素Fe 3+和G-四联体之间的相互作用清楚地表现在溶剂H-1/H-2同位素对顺磁移动血红素甲基质子信号的NMR参数的影响中，并且血红素Fe 3+与两个G-四联体的八个羰基氧原子的相互作用被示出提供围绕血红素Fe 3+的强的和轴对称的配体场，产生具有高度对称的血红素电子结构的血红素（Fe 3+）低自旋物质。这一发现为设计各种血红素-DNA复合物的分子结构和功能特性提供了新的见解。
The structure of a complex between heme(Fe3+) and a parallel G-quadruplex DNA formed from a single repeat sequence of the human telomere, d(TTAGGG), has been characterized by H-1 NMR The study demonstrated that the heme(Fe3+) is sandwiched between the 3'-terminal G-quartets of the G-quadruplex DNA. Hence, the net +1 charge of the heme(Fe3+) in the complex is surrounded by the eight carbonyl oxygen atoms of the G-quartets. Interaction between the heme Fe3+ and G-quartets in the complex was clearly manifested in the solvent H-1/H-2 isotope effect on the NMR parameters of paramagnetically shifted heme methyl proton signals, and interaction of the heme Fe3+ with the eight carbonyl oxygen atoms of the two G-quartets was shown to provide a strong and axially symmetric ligand field surrounding the heme Fe3+, yielding a heme(Fe3+) low-spin species with a highly symmetric heme electronic structure. This finding provides new insights as to the design of the molecular architecture and functional properties of various heme-DNA complexes.