Structure and Dynamics of Oligonucleotides in the Gas Phase

TitleStructure and Dynamics of Oligonucleotides in the Gas Phase
Publication TypeJournal Article
Year of Publication2015
AuthorsArcella, Annalisa, Dreyer Jens, Ippoliti Emiliano, Ivani Ivan, Portella Guillem, Gabelica Valérie, Carloni Paolo, and Orozco Modesto
JournalAngewandte Chemie International Edition
Date Published01/2015
Keywordsab initio calculations, DNA, gas phase, Mass Spectrometry, molecular dynamics

By combining ion-mobility mass spectrometry experiments with sub-millisecond classical and ab initio molecular dynamics we fully characterized, for the first time, the dynamic ensemble of a model nucleic acid in the gas phase under electrospray ionization conditions. The studied oligonucleotide unfolds upon vaporization, loses memory of the solution structure, and explores true gas-phase conformational space. Contrary to our original expectations, the oligonucleotide shows very rich dynamics in three different timescales (multi-picosecond, nanosecond, and sub-millisecond). The shorter timescale dynamics has a quantum mechanical nature and leads to changes in the covalent structure, whereas the other two are of classical origin. Overall, this study suggests that a re-evaluation on our view of the physics of nucleic acids upon vaporization is needed.