Intermolecular interactions between nucleoside, amino acid, and water molecules probed by ultraviolet photodissociation in the gas phase

The effects of intermolecular interactions on the reactivity of hydrogen-bonded clusters of adenosine and tryptophan (Trp) in the gas phase were investigated by water adsorption and ultraviolet photoexcitation. The product ion spectra of photoexcited H+(Trp)(adenosine) and its hydrated clusters were obtained at 8 K using a tandem mass spectrometer equipped with an electrospray ionization source and a cold ion trap. The primary product ion of photoexcitated H+(Trp)(adenosine) was H+(adenine), which was formed via Trp detachment and glycosidic bond cleavage of adenosine. The primary product ion formed after the photoexcitation of H+(Trp)(adenosine) (H2O)n was H+(adenosine), which resulted from the detachment of Trp and water molecules. The relative abundance of H+(adenosine) was substantially higher than that of H+(adenine), indicating that water adsorption on H+(Trp)(adenosine) weakened the intermolecular interactions between Trp and adenosine and inhibited the photoinduced glycosidic bond cleavage of adenosine in the clusters.

Automated summary

The effects of intermolecular interactions on the reactivity of hydrogen-bonded clusters of adenosine and tryptophan in the gas phase were investigated using water adsorption and ultraviolet photoexcitation. The results showed that water adsorption weakened the intermolecular interactions between adenosine and tryptophan in the clusters and inhibited the photoinduced glycosidic bond cleavage of adenosine.