Radiation-Induced Molecular Processes in DNA: A Perspective on Gas-Phase Interaction Studies

Studying the direct effects of DNA irradiation is essential for understanding the impact of radiation on biological systems. Gas-phase interactions are especially well suited to uncover the molecular mechanisms underlying these direct effects. Only relatively recently, isolated DNA oligonucleotides were irradiated by ionizing particles such as VUV or X-ray photons or ion beams, and ionic products were analyzed by mass spectrometry. This article provides a comprehensive review of primarily experimental investigations in this field over the past decade, emphasizing the description of processes such as ionization, fragmentation, charge and hydrogen transfer triggered by photoabsorption or ion collision, and the recent progress made thanks to specific atomic photoabsorption. Then, we outline ongoing experimental developments notably involving ion-mobility spectrometry, crossed beams or time-resolved measurements. The discussion extends to potential research directions for the future. This perspective explores the technical developments towards crossed-beam studies of ionizing radiation with mass-selected and conformationally pure beams of oligonucleotide ions. It reviews key developments in the field and highlights challenges. The relevance of expected future results as benchmarks for quantum chemical calculations and for multiscale-modelling of radiation therapy is outlined. image