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A post‐SCF quantum chemistry study on local minima of 8‐oxo‐guanine stacked with all four nucleic acid bases in B‐DNA conformations
Author(s) -
Cysewski Piotr,
CzyżnikowskaBalcerak Żaneta
Publication year - 2007
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570440403
Subject(s) - chemistry , guanine , nucleic acid , dna , nucleobase , crystallography , stereochemistry , context (archaeology) , computational chemistry , nucleotide , biochemistry , paleontology , biology , gene
AbstractThe post SCF MP2/6‐31G*(d=0.25) method was applied to obtain potential energy surface of 8‐oxoguanine stacked with all four canonical DNA bases. The spatial neighbourhood was scanned of stacked complexes found in the native B‐DNA. The presented results suggest that the hydroxyl radical modification of guanine at C 8 position has significant impact on structural, energetic, orbital and electrostatic properties of stacked complexes with canonical DNA bases. The pair stabilization energy, including electron correlation terms, suggests that the 5′‐A/GA‐3′ pair is the most stable among all of the studied complexes. The 8‐oxo‐guanine has been found as a source of significant changes in electroaccepting properties compared to stacked pairs formed by canonical guanine since both electron affinities and localization of HOMO orbital were altered. However, electro‐donation abilities are not modified after replacement of guanine with 8‐oxo‐guanine irrespectively on the context of B‐DNA bases.