核酸碱基与甘氨酸二肽间氢键作用的最佳位点  

Site Preferences of Nucleic Acid Bases Hydrogen Bonding to Glycine Dipeptide

作　　者：刘畅[1] 于歌[1] 黄翠英[1] 王长生[1] 

机构地区：[1]辽宁师范大学化学化工学院,大连116029

出　　处：《化学学报》2015年第4期357-365,共9页Acta Chimica Sinica

基　　金：国家自然科学基金(No.21173109);辽宁省优秀人才基金(No.LR2012037);大连市领军人才资助~~

摘　　要：优化得到了碱基腺嘌呤、胸腺嘧啶、尿嘧啶、鸟嘌呤及胞嘧啶与甘氨酸二肽分子形成的28个氢键复合物的稳定结构并计算了结合能,探讨了五种碱基与甘氨酸二肽分子间氢键作用的最佳位点.本文研究发现:每种碱基均可以通过不同位点与二肽分子形成氢键复合物,腺嘌呤、胸腺嘧啶、尿嘧啶、鸟嘌呤及胞嘧啶分别最倾向使用A3、T1、U1、G3及C1位点与甘氨酸二肽分子形成氢键复合物;碱基分子某位点的质子化反应焓变越负所形成的氢键复合物越稳定,去质子化反应焓变越小所形成的氢键复合物越稳定;由氢键复合物的结合能计算得到的稳定性次序与由碱基分子质子化和去质子化反应焓变推得的稳定性次序一致.The optimal structures of twenty-eight hydrogen-bonded complexes, containing one glycine dipeptide molecule and one of the nucleic acid base adenine, thymine, uracil, guanine and cytosine, were obtained at the B3LYP/6-31 q-G（d,p） level. The binding energies of these complexes were further evaluated at the CP-corrected MP2/aug-cc-pVTZ level. The site-preferences of the five nucleic acid bases hydrogen bonding to glycine dipeptide are explored. The calculation results show that any of the five nucleic acid bases can hydrogen bond to glycine dipeptide through different binding site. The hy- drogen-bonded complexes formed through site A3 of adenine, site T1 of thymine, site U1 of uracil, site C1 of cytosine and site G3 of guanine are the most stable. The stability of the hydrogen-bonded complexes is associated with the enthalpy change of the protonation/deprotonation reaction of the nucleic acid bases. The more negative the enthalpy change of the protonation reaction or the smaller the enthalpy change of the deprotonation reaction, the more stable the hydrogen-bonded complexes.

关 键 词：甘氨酸二肽 核酸碱基 氢键复合物 结合能 质子化反应 去质子化反应 

分 类 号：O641.1[理学—物理化学]