氨基酸侧链与氧化鸟嘌呤碱基对体系的氢键作用

发布时间：2018-08-18 18:18

【摘要】：应用量子化学方法,分别在气相和水溶液中对氨基酸侧链与氧化鸟嘌呤碱基对(8-oxo-G∶C)形成的三体复合物的氢键键能、几何结构、电荷分布及二阶稳定化能进行了研究.结果表明,水溶液的存在削弱了复合物中的氢键强度,电荷分布变化明显,水溶液中形成氢键位点的电荷变化量约为气相中的10倍,而几何结构变化不明显、对于酶与DNA之间的相互作用的研究需在水溶液中进行.水溶液对带电三体复合物中8-oxo-G∶C与氨基酸侧链间的氢键有较大影响,键能平均减小了69.23 k J/mol,不带电复合物仅减小了3.60k J/mol.水溶液中三体复合物中8-oxo-G∶C间的氢键受侧链的影响不大,且与侧链带电与否无关,带电复合物和不带电复合物的氢键强度分别减小了24.57和30.05 k J/mol,且二阶稳定化能越大,其对应的氢键键长越短.
[Abstract]:The hydrogen bond energy, geometric structure, charge distribution and second order stabilization energy of three-body complexes formed by side chain of amino acid with guanine base pair oxide (8-oxo-G:C) in gas phase and aqueous solution were studied by quantum chemical method. The results show that the existence of aqueous solution weakens the hydrogen bond strength in the complex, and the charge distribution changes obviously. The charge change of the hydrogen bond site in the aqueous solution is about 10 times of that in the gas phase, but the geometric structure does not change obviously. The interaction between enzyme and DNA needs to be studied in aqueous solution. The hydrogen bond between 8-oxo-G:C and the side chain of amino acid was greatly affected by aqueous solution. The average bond energy decreased by 69.23kJ / mol and the uncharged complex only decreased by 3.60kJ / mol. The hydrogen bond between 8-oxo-G:C in aqueous solution is not affected by the side chain, and it is independent of the charge of the side chain. The hydrogen bond strength of charged and uncharged complexes decreases 24.57 and 30.05kJ / mol, respectively, and the second order stabilization energy increases. The shorter the hydrogen bond length is.
【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:21133005,21603091) 辽宁省教育厅一般项目(批准号:L2014426) 辽宁师范大学创新实践项目(批准号:cx20170113)资助~~
【分类号】：O641.3

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