Jean-Yves Salpin, Sébastien Guillaumont, Daniel Ortiz, Jeanine Tortajada, Philippe Maître
Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, Université d'Evry Val d'Essonn e, Bâtiment Maupertuis, Boulevard François Mitterrand, 91025 Evry, France. jean-yves.salpin@univ-evry.fr
Inorganic chemistry 2011 Aug 15The structure of the [Pb(UMP)-H](+) (UMP = uridine-5'-monophosphate) complex was studied in the gas phase by combining electrospray ionization (ESI), tandem mass spectrometry, and mid-infrared multiple photon dissociation (IRMPD) spectroscopy. The results obtained show that Pb(2+) ions interact not only with the deprotonated phosphate group but also with a carbonyl group of the nucleobase moiety by folding of the mononucleotide, resulting in macrochelates that are not likely to be present in solution. Comparison between the IRMPD and DFT-computed spectra suggests that the ESI-generated complex likely corresponds to a mixture of several structures, and establishes the enolic tautomers as the most abundant species for the [Pb(UMP)-H](+) ion, while the very weak IRMPD signal observed at ∼1763 cm(-1) points to a minor population of oxo forms. Our data also suggest that losing the nucleobase residue under CID conditions does not necessarily mean a lack of interaction between the metal and the nucleobase moiety, as commonly reported in the literature for large oligonucleotides. © 2011 American Chemical Society
Jean-Yves Salpin, Sébastien Guillaumont, Daniel Ortiz, Jeanine Tortajada, Philippe Maître. Direct evidence for tautomerization of the uracil moiety within the Pb2+/uridine-5'-monophosphate complex: a combined tandem mass spectrometry and IRMPD study. Inorganic chemistry. 2011 Aug 15;50(16):7769-78
PMID: 21744847
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