Solution structural studies of molybdate-nucleotide polyanions.
The complexation of molybdate with the nucleotides adenosine-5'-monophosphate (5'-AMP), adenosine-3'-monophosphate (3'-AMP) and guanosine-5'-monophosphate (5'-GMP) has been investigated by (1)H and (31)P NMR and Mo K-edge X-ray absorption near edge (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy. Acidification of aqueous solutions containing molybdate and each of the nucleotides resulted in the formation of a single species characterized by (1)H resonances which are deshielded relative to those of free nucleotide. Analysis of the two-component systems indicated a Mo/nucleotide ratio of 2.5:1 for the complexation species. White compounds, characterized as Na(2)[Mo(5)O(15)(HB)(2)] (B=5'-AMP, 5'-GMP), have been isolated from the acidified molybdate/H(2)B solutions. Dissolution in D(2)O replicates the NMR spectra of the solution species observed prior to precipitation. Solution and solid state Mo K-edge XAS and EXAFS spectroscopy of Na(2)[Mo(5)O(15)(HAMP)(2)] and Na(6)[Mo(5)O(15)(PO(4))(2)] provide convincing evidence for the presence of a pentamolybdodiphosphate core in the molybdate-nucleotide complexes in both the solid and solution states.
Hill
Lyndal M R
LM
School of Chemistry, University of Melbourne, Victoria 3010, Melbourne, Australia.
George
Graham N
GN
Duhme-Klair
Anne Kathrin
AK
Young
Charles G
CG
D000249:Adenosine Monophosphate / Q000737:chemistry*; D006157:Guanosine Monophosphate / Q000737:chemistry*; D008958:Models, Molecular; D008982:Molybdenum / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D013052:Spectrometry, X-Ray Emission / Q000379:methods
C044659:molybdate; D000249:Adenosine Monophosphate; D008982:Molybdenum; D006157:Guanosine Monophosphate