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Density functional theory and topological analysis on the hydrogen bonding interactions in cysteine‐thymine complexes
Author(s) -
Huang Zhengguo,
Yu Lei,
Dai Yumei
Publication year - 2010
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.22772
Subject(s) - hydrogen bond , chemistry , intermolecular force , natural bond orbital , atoms in molecules , density functional theory , crystallography , low barrier hydrogen bond , molecule , computational chemistry , hydrogen atom , organic chemistry , group (periodic table)
Hydrogen bonding interactions between amino acids and nucleic acid bases constitute the most important interactions responsible for the specificity of protein binding. In this study, complexes formed by hydrogen bonding interactions between cysteine and thymine have been studied by density functional theory. The relevant geometries, energies, and IR characteristics of hydrogen bonds (H‐bonds) have been systematically investigated. The quantum theory of atoms in molecule and natural bond orbital analysis have also been applied to understand the nature of the hydrogen bonding interactions in complexes. More than 10 kinds of H‐bonds including intra‐ and intermolecular H‐bonds have been found in complexes. Most of intermolecular H‐bonds involve O (or N) atom as H‐acceptor, whereas the H‐bonds involving C or S atom usually are weaker than other ones. Both the strength of H‐bonds and the structural deformation are responsible for the stability of complexes. Because of the serious deformation, the complex involving the strongest H‐bond is not the most stable structures. Relationships between H‐bond length (Δ R X‐H ), frequency shifts (Δ v ), and the electron density (ρ b ) and its Laplace (▿ 2 ρ b ) at bond critical points have also been investigated. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011