title: Combinatorial multinuclear NMR and X-ray diffraction studies of uranium(VI)-nucleotide complexes.
abstract: The complex formation of uranium(VI) with four nucleotides, adenosine- (AMP), guanosine- (GMP), uridine- (UMP), and cytidine-monophosphate (CMP), has been studied in the alkaline pH range (8.5-12) by (1)H, (31)P, (13)C, and (17)O NMR spectroscopy, providing spectral integral, chemical shift, homo- and heteronuclear coupling, and diffusion coefficient data. We find that two and only two complexes are formed with all ligands in the investigated pH region independently of the total uranium(VI) and ligand concentrations. Although the coordination of the 5'-phosphate group and the 2'- and 3'-hydroxyl groups of the sugar unit to the uranyl ions is similar to that proposed earlier ("Feldman complex"), the number and the structures of the complexes are different. The uranium-to-nucleotide ratio is 6:4 in one of the complexes and 3:3 in the other one, as unambiguously determined by a combinatorial approach using a systematic variation of the ratio of two ligands in ternary uranium(VI)-nucleotide systems. The structure of the 3:3 complex has been determined by single-crystal diffraction as well, and the results confirm the structure proposed by NMR in aqueous solution. The results have important implications on the synthesis of oligonucleotides.
authors.affiliation: Inorganic Chemistry and Physical Chemistry, Department of Chemistry, Royal Institute of Technology (KTH), S-10044 Stockholm, Sweden. zoltan@kth.se
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Szabó
authors.forename: István
authors.initials: I
authors.lastname: Furó
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Csöregh
mesh_terms: D000249:Adenosine Monophosphate / Q000737:chemistry; D003568:Cytidine Monophosphate / Q000737:chemistry; D004058:Diffusion; D006157:Guanosine Monophosphate / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D009711:Nucleotides / Q000737:chemistry*; D014501:Uranium / Q000737:chemistry*; D014542:Uridine Monophosphate / Q000737:chemistry; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D008024:Ligands; D009711:Nucleotides; D000249:Adenosine Monophosphate; D014501:Uranium; D006157:Guanosine Monophosphate; D014542:Uridine Monophosphate; D003568:Cytidine Monophosphate