title: CH/pi interactions in DNA and proteins. A theoretical study.
abstract: A systematic study of the CH/pi interactions of methane with the purine and pyrimidine bases of nucleic acids and with the lateral chains of the four natural aromatic amino acids has been carried out for the first time. The MPWB1K/6-31+G(d,p) method has shown to be adequate for the study of these weak interactions in which dispersion forces play a main role. It has been shown that two different kinds of clusters exist, depending on whether one or two CH bonds point to the aromatic system. The latter one, which we have called bifurcated, is usually more stable. With regard to aromatic amino acids, our calculations agree with experimental data in the fact that tryptophan leads to the strongest interaction, while hystidine leads to the weakest one. In the case of nucleic acid bases, the differences in binding energies are not large. This is specially true for thymine and uracil, showing that these two bases have a similar acceptor character in CH/pi interactions.
authors.affiliation: Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: Adrià
authors.initials: A
authors.lastname: Gil
authors.forename: Vicenç
authors.initials: V
authors.lastname: Branchadell
authors.forename: Joan
authors.initials: J
authors.lastname: Bertran
authors.forename: Antoni
authors.initials: A
authors.lastname: Oliva
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D001554:Benzene / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D003198:Computer Simulation; D004247:DNA / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D008697:Methane / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D011506:Proteins / Q000737:chemistry*; D013499:Surface Properties; D013941:Thymine / Q000737:chemistry; D014498:Uracil / Q000737:chemistry
chemical_list: D000596:Amino Acids; D011506:Proteins; D014498:Uracil; D002244:Carbon; D006859:Hydrogen; D004247:DNA; D001554:Benzene; D008697:Methane; D013941:Thymine