title: Metal-assisted proton transfer reaction in base pairs.
abstract: We investigated the proton-transfer reactions in guanine-cytosine (GC) pairs with density functional theories. In the GC pair bound to cis-platin, the barrier height of proton-transfer reaction dramatically decreases in comparison with the GC pair without the cis-platin. This is because (a) successive processes of charge transfer from G to cisplatin thereby stabilizing both the GC and G*C pairs and (b) an additional hydrogen bond between G and the ligand of Pt atom. In two GC pairs bound to the cis-platin, the single proton-transfer reaction occurs in one of the two GC pairs. No simultaneous single proton-transfer reaction can occur in both base pairs. From the geometry optimization, two different single proton-transferred structures (cis-(CG*)d-Pt-(GC)p and cis-(CG)d-Pt-(G*C)p, where * means a proton donor of G) are as stable as the original structures (CG)d-Pt-(GC)p.
authors.affiliation: Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan. matsui@qcl.t.u-tokyo.ac.jp
authors.forename: Toru
authors.initials: T
authors.lastname: Matsui
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Shigeta
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Hirao
mesh_terms: D020029:Base Pairing; D002945:Cisplatin / Q000737:chemistry*; D003596:Cytosine / Q000737:chemistry*; D006147:Guanine / Q000737:chemistry*; D006860:Hydrogen Bonding; D011522:Protons
chemical_list: D011522:Protons; D006147:Guanine; D003596:Cytosine; D002945:Cisplatin