title: N-methylformamide-benzene complex as a prototypical peptide N-H...pi hydrogen-bonded system: density functional theory and MP2 studies.
abstract: Although the existence of peptide N-H...pi hydrogen bonds recently has been reported in protein structures, little is known about their strength and binding nature and, therefore, the relative importance of the interaction. To shed light on this binding, the N-methylformamide-benzene complex, as a model of the peptide N-H...pi hydrogen bonding, was studied by using density functional theory and Møller-Plesset second-order perturbation (MP2) methods. The geometry of the complex was fully optimized at the B3LYP/6-31G(d,p) and MP2/6-31G(d,p) levels. The optimized interaction distances are about 3.6 and 3.2 A, respectively, at the two levels. The binding energy corrected by basis set superposition error with the MP2/cc-pVTZ method based on the MP2/6-31G geometry is -4.37 kcal/mol, which is as strong as the conventional hydrogen bonding. The calculated results suggest that the peptide N-H...pi hydrogen bonding is of sufficient strength to play an important role in the stabilization of protein structures. These results are helpful to better understand the characteristics and nature of the peptide N-H...pi interaction as well as to modify current force fields to better represent this special interaction.
authors.affiliation: Center for Drug Discovery and Design, State Key Laboratory of New Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People's Republic of China.
authors.forename: Jiagao
authors.initials: J
authors.lastname: Cheng
authors.forename: Congmin
authors.initials: C
authors.lastname: Kang
authors.forename: Weiliang
authors.initials: W
authors.lastname: Zhu
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Luo
authors.forename: Chum Mok
authors.initials: CM
authors.lastname: Puah
authors.forename: Kaixian
authors.initials: K
authors.lastname: Chen
authors.forename: Jianhua
authors.initials: J
authors.lastname: Shen
authors.forename: Hualiang
authors.initials: H
authors.lastname: Jiang
mesh_terms: D001554:Benzene / Q000737:chemistry*; D004583:Electrons; D005559:Formamides / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry*
chemical_list: D005559:Formamides; D010455:Peptides; D001554:Benzene; C002950:methylformamide