title: Nitrogen K-edge X-ray absorption near edge structure (XANES) spectra of purine-containing nucleotides in aqueous solution.
abstract: The N K-edge X-ray absorption near edge structure (XANES) spectra of the purine-containing nucleotide, guanosine 5'-monophosphate (GMP), in aqueous solution are measured under various pH conditions. The spectra show characteristic peaks, which originate from resonant excitations of N 1s electrons to π* orbitals inside the guanine moiety of GMP. The relative intensities of these peaks depend on the pH values of the solution. The pH dependence is explained by the core-level shift of N atoms at specific sites caused by protonation and deprotonation. The experimental spectra are compared with theoretical spectra calculated by using density functional theory for GMP and the other purine-containing nucleotides, adenosine 5'-monophosphate, and adenosine 5'-triphosphate. The N K-edge XANES spectra for all of these nucleotides are classified by the numbers of N atoms with particular chemical bonding characteristics in the purine moiety.
authors.affiliation: Department of Applied Physics, Tokyo University of Agriculture and Technology, Koganei-shi, Tokyo 184-8588, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shimada
authors.affiliation: Department of Applied Physics, Tokyo University of Agriculture and Technology, Koganei-shi, Tokyo 184-8588, Japan.
authors.forename: Taishi
authors.initials: T
authors.lastname: Fukao
authors.affiliation: Department of Applied Physics, Tokyo University of Agriculture and Technology, Koganei-shi, Tokyo 184-8588, Japan.
authors.forename: Hirotake
authors.initials: H
authors.lastname: Minami
authors.affiliation: Department of Applied Physics, Tokyo University of Agriculture and Technology, Koganei-shi, Tokyo 184-8588, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Ukai
authors.affiliation: Advanced Science Research Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Fujii
authors.affiliation: Advanced Science Research Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan.
authors.forename: Akinari
authors.initials: A
authors.lastname: Yokoya
authors.affiliation: Synchrotron Radiation Research Center, Japan Atomic Energy Agency, Sayo-gun, Hyougo 679-5148, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Fukuda
authors.affiliation: Synchrotron Radiation Research Center, Japan Atomic Energy Agency, Sayo-gun, Hyougo 679-5148, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Saitoh
mesh_terms: D001665:Binding Sites; D003198:Computer Simulation; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D008958:Models, Molecular; D009584:Nitrogen / Q000737:chemistry*; D009711:Nucleotides / Q000737:chemistry*; D011687:Purines / Q000737:chemistry*; D012996:Solutions; D013052:Spectrometry, X-Ray Emission / Q000379:methods*; D014867:Water / Q000737:chemistry*
chemical_list: D009711:Nucleotides; D011687:Purines; D012996:Solutions; D014867:Water; D009584:Nitrogen; C030985:purine