One-Electron Oxidation of Individual DNA Bases and DNA Base Stacks
Document Type
Article
Publication Date
3-1-2010
Description
In calculations performed with DFT there is a tendency of the purine cation to be delocalized over several bases in the stack. Attempts have been made to see if methods other than DFT can be used to calculate localized cations in stacks of purines, and to relate the calculated hyperflne couplings with known experimental results. To calculate reliable hyperflne couplings it is necessary to have an adequate description of spin polarization which means that electron correlation must be treated properly. UMP2 theory has been shown to be unreliable in estimating spin densities due to overestimates of the doubles correction. Therefore attempts have been made to use quadratic configuration interaction (UQCLSD) methods to treat electron correlation. Calculations on the individual. DNA bases are presented to show that with UQCISD methods it is possible to calculate hyperflne couplings in good agreement with the experimental results. However these UQCISD calculations are far more time-consuming than DFT calculations. Calculations are then extended to two stacked guanine bases. Preliminary calculations with UMP2 or UQCISD theory on two stacked guanines lead to a cation localized on a single guanine base.
Citation Information
Close, David M.. 2010. One-Electron Oxidation of Individual DNA Bases and DNA Base Stacks. Journal of Physical Chemistry A. Vol.114(4). 1860-1867. https://doi.org/10.1021/jp906963f PMID: 20050713 ISSN: 1089-5639