辽宁师范大学学报（自然科学版）
遼寧師範大學學報（自然科學版）
료녕사범대학학보（자연과학판）
JOURNAL OF LIAONING NORMAL UNIVERSITY(NATURAL SCIENCE)
2013年
3期
369-372
,共4页
碱土离子%核酸碱基%水%量子化学计算%相互作用能%电荷分布
堿土離子%覈痠堿基%水%量子化學計算%相互作用能%電荷分佈
감토리자%핵산감기%수%양자화학계산%상호작용능%전하분포
alkaline-earth cations%nucleic acid bases%water%quantum chemical calculation%interaction energy%charge distribution
采用高水平量子化学方法，MP2/6-311G（d ，p），对气相中的Mg2＋/Ca2＋与DNA碱基和水的相互作用进行了研究，优化base-M-（H2 O ）n （M ＝ M g2＋/Ca2＋，n＝1～2）的几何结构，计算其结合能和电荷分布等性质．结果表明，M g2＋与配体碱基及水的距离要比Ca2＋与其配体距离更近，M g2＋与其配体的平均距离要比Ca2＋小0．03 nm左右．M g2＋与其配体的结合能要比Ca2＋的大60～70 kcal/mol左右，随着水数目的增加，离子与配体的结合能力逐渐减弱，M g2＋/Ca2＋到水和碱基的平均距离越来越大，但变化幅度较小．金属离子的电荷主要转移到水中．
採用高水平量子化學方法，MP2/6-311G（d ，p），對氣相中的Mg2＋/Ca2＋與DNA堿基和水的相互作用進行瞭研究，優化base-M-（H2 O ）n （M ＝ M g2＋/Ca2＋，n＝1～2）的幾何結構，計算其結閤能和電荷分佈等性質．結果錶明，M g2＋與配體堿基及水的距離要比Ca2＋與其配體距離更近，M g2＋與其配體的平均距離要比Ca2＋小0．03 nm左右．M g2＋與其配體的結閤能要比Ca2＋的大60～70 kcal/mol左右，隨著水數目的增加，離子與配體的結閤能力逐漸減弱，M g2＋/Ca2＋到水和堿基的平均距離越來越大，但變化幅度較小．金屬離子的電荷主要轉移到水中．
채용고수평양자화학방법，MP2/6-311G（d ，p），대기상중적Mg2＋/Ca2＋여DNA감기화수적상호작용진행료연구，우화base-M-（H2 O ）n （M ＝ M g2＋/Ca2＋，n＝1～2）적궤하결구，계산기결합능화전하분포등성질．결과표명，M g2＋여배체감기급수적거리요비Ca2＋여기배체거리경근，M g2＋여기배체적평균거리요비Ca2＋소0．03 nm좌우．M g2＋여기배체적결합능요비Ca2＋적대60～70 kcal/mol좌우，수착수수목적증가，리자여배체적결합능력축점감약，M g2＋/Ca2＋도수화감기적평균거리월래월대，단변화폭도교소．금속리자적전하주요전이도수중．
By applying a high-level quantum chemistry (QM ) method ,the interactions between Mg2+ /Ca2+ with DNA bases and water in gas-phase were investigated .The structures ,binding energies and charge distributions of base-M-(H2 O)n (M= Mg2+ /Ca2+ ,n=1~2) were studied .Results show that the distances of Mg2+-base and Mg2+-water are smaller than those of Ca2+ ,and the distances from the Mg2+ to H2O are 0 .03 nm smaller than those of Ca2+-H2O ;the binding energies between Mg2+and its ligands are 60~70 kcal/mol larger than those of Ca2+ .With the increasing number of water molecules ,the interactions between cation and its ligands reduce gradually ,the average distances from Mg2+ /Ca2+ to water and base enlarge gradually and insignificantly ,and the positive charges of Mg2+ /Ca2+ mainly transfer to water .
