GAS-PHASE CONFORMATIONS AND ENERGETICS OF SODIUM CATIONIZED 2_-DEOXYGUANOSINE AND GUANOSINE: IRMPD ACTION SPECTROSCOPY AND THEORETICAL STUDIES

Zhu, Yanlong

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https://hdl.handle.net/2142/79246 Copy

Description

Title

GAS-PHASE CONFORMATIONS AND ENERGETICS OF SODIUM CATIONIZED 2_-DEOXYGUANOSINE AND GUANOSINE: IRMPD ACTION SPECTROSCOPY AND THEORETICAL STUDIES

Author(s)

Zhu, Yanlong

Contributor(s)

• Oomens, J.
• Gao, Juehan
• Rodgers, M.T.
• Bao, Xun
• He, Chenchen
• Hamlow, Lucas

Issue Date

22-Jun-15

Keyword(s)

Ions

Abstract

In living systems, the local structures of DNA and RNA are influenced by protonation, deprotonation and noncovalent binding interactions with cations. In order to determine the effects of Na$^{+}$ cationization on the gas-phase structures of $2^prime$-deoxyguanosine, [dGuo+Na]$^{+}$, and guanosine, [Guo+Na]$^{+}$, infrared multiple photon dissociation (IRMPD) action spectra of these two sodium cationized DNA and RNA mononucleosides are measured over the range extending from ~500 to ~1850 cm$^{-1}$ using the FELIX free electron laser. Complementary electronic structure calculations are performed to determine the stable low-energy conformations of these complexes. Geometry optimizations and frequency analyses of these species are performed at the B3LYP/6-31G* level of theory, whereas single-point energies are calculated at the B3LYP/6-311+G(2d,2p) level of theory to determine the relative stabilities of these conformations. Comparison of the measure IRMPD action spectra and computed linear IR spectra enable the conformations accessed in the experiments to be elucidated. In both cases, preferential binding of the Na$^{+}$ cation to O6 and N7 positions of the nucleobase is observed. Present results for the sodium cationized nucleosides are compared to results for the analogous protonated forms of these nucleosides to elucidate the effects of multiple chelating interactions with the sodium cation to hydrogen bonding interactions in the protonated systems on the structures and stabilities of these nucleosides.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

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http://hdl.handle.net/2142/79246

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