Interaction of Adenine Adducts with Thymine: A Computational Study
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- 作者：Prabhat K. Sahu ; Chang-Wang Kuo ; Shyi-Long Lee
- 刊名：Journal of Physical Chemistry B
- 出版年：2007
- 出版时间：March 22, 2007
- 年：2007
- 卷：111
- 期：11
- 页码：2991 - 2998
- 全文大小：424K
- 年卷期：v.111,no.11(March 22, 2007)
- ISSN：1520-5207
文摘
The existence of DNA adducts bring the danger of carcinogenesis because of mispairing with normal DNAbases. 1,N6-ethenoadenine adducts (
A) and 1,N6-ethanoadenine adducts (EA) have been considered as DNAadducts to study the interaction with thymine, as DNA base. Several different stable conformers for eachtype of adenine adduct with thymine, [A(1)-T(I), A(2)-T(I), A(3)-T(I) and EA(1)-T(I), EA(2)-T(I),EA(3)-T(I)] and [A(1)-T(II), A(2)-T(II), A(3)-T(II) and EA(1)-T(II), EA(2)-T(II), EA(3)-T(II)],have been considered with regard to their interactions. The differences in their geometrical structures, energeticproperties, and hydrogen-bonding strengths have also been compared with Watson-Crick adenine-thyminebase pair (A-T). Single-point energy calculations at MP2/6-311++G** levels on B3LYP/6-31+G* optimizedgeometries have also been carried out to better estimate the hydrogen-bonding strengths. The basis setsuperposition error corrected hydrogen-bonding strength sequence at MP2/6-311++G**//B3LYP/6-31+G*for the most stable complexes is found to be EA(2)-T(I) (15.30 kcal/mol) > EA(1)-T(II) (14.98 kcal/mol)> EA(3)-T(II) (14.68 kcal/mol) > A(2)-T(I) (14.54 kcal/mol) > A(3)-T(II) (14.22 kcal/mol) > A(3)-T(II) (13.64 kcal/mol) > A-T (13.62 kcal/mol). The calculated reaction enthalpy value for A(2)-T(I)is 10.05 kcal/mol, which is the highest among the etheno adduct-thymine complexes and about 1.55 kcal/mol more than those obtained for Watson-Crick A-T base pair and the reaction enthalpy value for EA(1)-T(II) is 10.22 kcal/mol, which is highest among the ethano addcut-thymine complexes and about 1.72 kcal/mol more than those obtained for Watson-Crick A-T base pair. The aim of this research is to providefundamental understanding of adenine adduct and thymine interaction at the molecular level and to aid infuture experimental studies toward finding the possible cause of DNA damage.
A) and 1,N6-ethanoadenine adducts (EA) have been considered as DNAadducts to study the interaction with thymine, as DNA base. Several different stable conformers for eachtype of adenine adduct with thymine, [A(1)-T(I), A(2)-T(I), A(3)-T(I) and EA(1)-T(I), EA(2)-T(I),EA(3)-T(I)] and [A(1)-T(II), A(2)-T(II), A(3)-T(II) and EA(1)-T(II), EA(2)-T(II), EA(3)-T(II)],have been considered with regard to their interactions. The differences in their geometrical structures, energeticproperties, and hydrogen-bonding strengths have also been compared with Watson-Crick adenine-thyminebase pair (A-T). Single-point energy calculations at MP2/6-311++G** levels on B3LYP/6-31+G* optimizedgeometries have also been carried out to better estimate the hydrogen-bonding strengths. The basis setsuperposition error corrected hydrogen-bonding strength sequence at MP2/6-311++G**//B3LYP/6-31+G*for the most stable complexes is found to be EA(2)-T(I) (15.30 kcal/mol) > EA(1)-T(II) (14.98 kcal/mol)> EA(3)-T(II) (14.68 kcal/mol) > A(2)-T(I) (14.54 kcal/mol) > A(3)-T(II) (14.22 kcal/mol) > A(3)-T(II) (13.64 kcal/mol) > A-T (13.62 kcal/mol). The calculated reaction enthalpy value for A(2)-T(I)is 10.05 kcal/mol, which is the highest among the etheno adduct-thymine complexes and about 1.55 kcal/mol more than those obtained for Watson-Crick A-T base pair and the reaction enthalpy value for EA(1)-T(II) is 10.22 kcal/mol, which is highest among the ethano addcut-thymine complexes and about 1.72 kcal/mol more than those obtained for Watson-Crick A-T base pair. The aim of this research is to providefundamental understanding of adenine adduct and thymine interaction at the molecular level and to aid infuture experimental studies toward finding the possible cause of DNA damage.