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Protonation of thymine, cytosine, adenine, and guanine DNA nucleic acid bases: Theoretical investigation into the framework of density functional theory
Author(s) -
Russo Nino,
Toscano Marirosa,
Grand André,
Jolibois Franck
Publication year - 1998
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/(sici)1096-987x(19980715)19:9<989::aid-jcc1>3.0.co;2-f
Subject(s) - thymine , tautomer , protonation , chemistry , guanine , cytosine , proton , computational chemistry , density functional theory , nucleic acid , bond length , nucleobase , affinities , hydrogen bond , dna , stereochemistry , crystallography , nucleotide , molecule , ion , physics , organic chemistry , quantum mechanics , biochemistry , crystal structure , gene
Gradient‐corrected density functional computations with triple‐zeta‐type basis sets were performed to determine the preferred protonation site and the absolute gas‐phase proton affinities of the most stable tautomer of the DNA bases thymine (T), cytosine (C), adenine (A), and guanine (G). Charge distribution, bond orders, and molecular electrostatic potentials were considered to rationalize the obtained results. The vibrational frequencies and the contribution of the zero‐point energies were also computed. Significant geometrical changes in bond lengths and angles near the protonation sites were found. At 298 K, proton affinities values of 208.8 (T), 229.1 (C), 225.8 (A), and 230.3 (G) kcal/mol were obtained in agreement with experimental results. © 1998 John Wiley & Sons, Inc. J Comput Chem 19: 989–1000, 1998