Probing Metal-Ion Purine Interactions at DNA Minor-Groove Sites
Probing Metal-Ion Purine Interactions at DNA Minor-Groove Sites
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DOI：
10.1021/ic9013448
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发表时间：
2009-11-02
影响因子：
4.6
通讯作者：
Houlton, Andrew
中科院分区：
文献类型：
--
作者：
Galindo, Miguel A.;Amantia, David;Houlton, Andrew
2-氨基基团对嘌呤碱的N3-位置处的金属离子结合的影响已经使用螯合物栓系衍生物进行了研究。二胺束缚的2，6-二氨基嘌呤（DAP）与二价d-区金属离子Cu（II）和Cd（II）的反应证实了结合可以发生，但这比腺嘌呤要少得多。在这方面，DAP类似于鸟嘌呤，其中我们先前已经观察到与腺嘌呤相比，二价金属离子通常缺乏N3结合（例如，Houlton等人，Angew.化学成分：Int.Ed.2000，39，2360; Chem.-2000，39，2360 EUR. J. 2000，6，4371）。对于单价d区金属离子Cu（I）和Ag（I），在固态下未观察到与腺嘌呤N3的结合，如通过与二硫醚系连的腺嘌呤衍生物的反应所示。相反，取决于反应的化学计量，分离（金属/配体比为1：2）或聚合（金属/配体比为1：1）络合物，并通过单晶X射线方法表征。在前者的核碱基是悬垂的，并参与碱基对相互作用，与沃森克里克…沃森-克里克和胡格斯汀存在Hoogsteen型配对。对于配位聚合物的一个相当意想不到的影响的系绳长度上的核碱基结合的网站上发现的桥接配体结合模式涉及的螯合二胺和腺嘌呤基。与较短的乙基系链衍生的聚合物链显示结合在N7位点的腺嘌呤，而结合在N1被发现在较长的丙基链长度。
The effect of the 2-amino group on metal ion binding at the N3-position of a purine base has been investigated using chelate-tethered derivatives. Reactions of diamine-tethered 2,6-diaminopurine (DAP) with divalent d-block metal ions Cu(II) and Cd(II) confirm that binding can occur, but this is much less prevalent than with adenine. In this regard DAP is similar to guanine where we have previously observed a general lack of N3-binding by divalent metal ions compared to adenine (e.g., Houlton et al., Angew. Chem., Int. Ed. 2000, 39, 2360; Chem.-Eur. J. 2000, 6, 4371). For the univalent d-block metals ions, Cu(I) and Ag(I), binding to adenine N3 is not observed in the solid state, as shown by reactions with dithioether-tethered adenine derivatives. Instead, depending on stoichiometry of the reaction, discrete (with metal/ligand ratio 1:2) or polymeric (with metal/ligand ratio 1:1) complexes were isolated and characterized by single crystal X-ray methods. In the former the nucleobases are pendant and involved in base-pair interactions, with both Watson-Crick...Watson-Crick and Hoogsteen...Hoogsteen type pairings present. For the coordination polymers a rather unexpected influence of the tether length on the site of nucleobase binding is found for bridging ligand binding modes involving the chelating diamine and the adeninyl group. Polymer chains derived with the shorter ethyl tether show binding at the N7 site of adeninyl, while binding at N1 is found in the longer propyl chain length.