ISSN:
0020-7608
Keywords:
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The electrostatic molecular potential minima around the guanine-cytosine base pair within a B-DNA minihelix are computed, taking into account the contributions of the sugar-phosphate backbone and of the adjacent base-pairs. The calculations are based on ab initio SCF wave functions of the different constituents of the nucleic acid. The results point to significant differences in the potential between the isolated nucleic acid bases or base-pairs and those within the DNA. Altogether the minima in the G-C regions are strongly enhanced in the minihelix. They benefit from the field created by the neighboring phosphates. From the purely electrostatic viewpoint an ambiguity remains as concerns the relative affinity of N7 and N3 of guanine for electrophiles. On the other hand, guanine should altogether be more susceptible than cytosine to such reagents, this ordering concerning also its NH2 group compared to that of cytosine.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/qua.560160219
