带电组氨酸侧链与DNA碱基间非键作用强度的理论研究

发布时间：2018-03-16 04:29

本文选题：组氨酸侧链　切入点：DNA碱基　出处：《高等学校化学学报》2017年01期 　论文类型：期刊论文

【摘要】：采用MP2方法和6-31+G(d,p)基组优化得到了带有一个正电荷的组氨酸侧链与4个DNA碱基间形成的18个氢键复合物的气相稳定结构,从文献中获取了组氨酸侧链与DNA碱基间形成的12个堆积和T型复合物的气相稳定结构,使用包含基组重叠误差(BSSE)校正的MP2方法和aug-cc-pVTZ基组及密度泛函理论M06-2X-D3方法和aug-cc-pVDZ基组计算了这些复合物的结合能.研究结果表明,包含BSSE校正的M06-2X-D3方法和aug-cc-pVDZ基组能够给出较准确的结合能;气相条件下,组氨酸侧链与同种DNA碱基间的离子氢键作用明显强于堆积作用和T型作用,组氨酸侧链最易通过离子氢键与胞嘧啶C和鸟嘌呤G作用形成氢键复合物,组氨酸与胞嘧啶C和鸟嘌呤G间的T型作用强于与腺嘌呤A和胸腺嘧啶T间的离子氢键作用;水相条件下,组氨酸侧链与同种DNA碱基间的离子氢键作用仍明显强于堆积作用和T型作用,组氨酸侧链更易与胞嘧啶C和鸟嘌呤G相互作用形成氢键复合物,但是最强的组氨酸侧链与胞嘧啶C间的T型作用明显弱于与腺嘌呤A和胸腺嘧啶T间的离子氢键作用,说明水相条件下组氨酸侧链与DNA碱基间主要通过离子氢键作用形成氢键复合物.
[Abstract]:The vapor-phase stable structure of 18 hydrogen bond complexes with a positive charge of histidine side chain and 4 DNA bases was obtained by using MP2 method and 6-31 GDX) base set optimization. The vapor stable structures of 12 stacked and T type complexes formed between the side chain of histidine and the base of DNA have been obtained from the literature. The binding energies of these complexes were calculated by using the MP2 method, the aug-cc-pVTZ basis set and the density functional theory M06-2X-D3 method and the aug-cc-pVDZ basis set, which included the basis set overlap error correction. The M06-2X-D3 method including BSSE correction and the aug-cc-pVDZ base set can give more accurate binding energy. In the gas phase, the ionic hydrogen bond between the side chain of histidine and the same DNA base is stronger than that between stacking and T type. The side chain of histidine is most likely to form hydrogen bond complex through the interaction of ion hydrogen bond with cytosine C and guanine G. the T-type interaction between histidine and cytosine C and guanine G is stronger than that with adenine A and thymine T. In aqueous phase, the ionic hydrogen bond between histidine side chain and homologous DNA base is still stronger than that between stacking and T type, and histidine side chain is easier to interact with cytosine C and guanine G to form hydrogen bond complex. However, the strongest T type interaction between histidine side chain and cytosine C was significantly weaker than that between adenine A and thymine T. The results show that the hydrogen bond complex is formed between the side chain of histidine and the base of DNA by the interaction of ionic hydrogen bond under the condition of water phase.
【作者单位】：辽宁师范大学化学化工学院;
【基金】：国家自然科学基金(批准号:21173109,21573098) 大连市领军人才项目资助~~
【分类号】：O641.3

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