Bond-specific fragmentation of peptides induced by swift heavy ions

• Applicant: Professor Dr. Michael Dürr
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry ; Experimental Condensed Matter Physics
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 547080370

The interaction of high-energy ions with organic or biological molecules and their ion-induced fragmentation play an important role in a wide variety of scientific questions including synthesis cycles of organic molecules in space, ion-based manufacturing processes, and tumor therapy with ion beams. Furthermore, from a fundamental point of view, the processes involved in ion-induced excitation of the molecular system and in particular the further energy distribution in the molecule are of great interest. However, the details of ion-induced fragmentation of more complex organic molecules are not well understood. Not least, this is due to a lack of appropriate experimental methods for analyzing ion-induced fragments in condensed biomolecular samples. Using a novel approach based on cluster-induced desorption/ionization in combination with mass spectrometry, we have recently shown that swift heavy ions lead to bond-specific bond cleavage in oligopeptides. This on a first glance surprising observation could be qualitatively explained on the basis of the excitation processes involved. In the proposed project, the relevant reaction processes and in particular the interplay between molecular structure and fragmentation behavior will be investigated by a detailed analysis of the fragments generated by means of swift heavy ions. The investigation will focus on peptide molecules: with their combination of the peptide backbone on the one hand and the functional groups on the other, they offer a wide range of possible variations in the molecular structure. Variation of ion energy and energy loss will provide further information about the processes involved. In addition, reactions of the generated (reactive) fragments will be investigated.

• DFG Programme: Research Grants