Molecular Mechanisms of Radiation Action on Peptides, Proteins, DNA Strands and Antibiotics Studied in the Gas Phase

Gas-phase studies are an ideal tool for the investigation of the molecular mechanisms underlying ionising radiation action upon biological systems. The field has strongly benefitted from the advent of electrospray ionisation as a tool for gentle transfer of complex biomolecular ions from solution into the gas phase. Radiofrequency techniques are commonly used for low-energy ion transport, manipulation, and trapping. The trapped molecular ions are then exposed to ionising radiation, e.g., from synchrotrons or heavy ion beamlines. The biomolecular interaction products are analysed by means of mass spectrometry. In this chapter, we provide a review of experimental investigations that focus on three different classes of biomolecular systems: peptides and proteins, DNA strands, and antibiotics. Molecular processes such as ionisation, fragmentation, and H transfer are discussed. The chapter closes with a brief description of current experimental developments towards conformational control through ion mobility spectrometry, electron spectroscopy in crossed-beam experiments, and time-resolved measurements, e.g., using ultrashort pulses from free electron lasers.