Back to Search
Start Over
PM6 quantum chemical study of the H-bonded and stacked associates of the adenine and thymine DNA bases: The nature of base stacking.
- Source :
-
Molecular Physics . 6/20/2008, Vol. 106 Issue 12/13, p1487-1494. 8p. 2 Diagrams, 6 Charts. - Publication Year :
- 2008
-
Abstract
- The planar H-bonded adenine-thymine (A • T) base pair and four stacked hetero associates (A/T) of these bases in a cluster containing 200 water molecules were studied by the new semi-empirical PM6 method. The formation of the planar A • T base pair in the water cluster was found to be energetically unfavourable, primarily due to the destabilising contribution of the base-water interactions. Under complete geometry optimisation, the planar A • T base pair converted into a nonplanar propeller-twisted and buckled associate. In contrast, the formation of all stacked dimers studied was found to be favourable, with formation energies ranging from -11 to -20 kcal/mol. The preference for the formation of these stacks results from the favourable change in the water structure and distortion of the paired and isolated bases during the base association reaction. [ABSTRACT FROM AUTHOR]
- Subjects :
- *ADENINE
*THYMINE
*MOLECULES
*CHEMICAL reactions
*BASES (Chemistry)
*WATER
Subjects
Details
- Language :
- English
- ISSN :
- 00268976
- Volume :
- 106
- Issue :
- 12/13
- Database :
- Academic Search Index
- Journal :
- Molecular Physics
- Publication Type :
- Academic Journal
- Accession number :
- 34294210
- Full Text :
- https://doi.org/10.1080/00268970802060682