000301010 001__ 301010
000301010 005__ 20190524175512.0
000301010 0247_ $$aG:(DE-HGF)2007_IVF-VH-NG-1104$$dVH-NG-1104
000301010 035__ $$aG:(DE-HGF)2007_IVF-VH-NG-1104
000301010 150__ $$aStructure and dynamics of gas-phase biomolecules studied by photon-induced ionization and dissociation$$y2016-2021
000301010 371__ $$0P:(DE-H253)PIP1014119$$aBari, Sadia
000301010 371__ $$0P:(DE-H253)PIP1008775$$aTechert, Simone
000301010 450__ $$aVH-NG-1104$$wd$$y2016-2021
000301010 5101_ $$0I:(DE-588b)5165524-X$$aHelmholtz Gemeinschaft Deutscher Forschungszentren$$bHGF
000301010 550__ $$0G:(DE-HGF)IVF-20140101$$aImpuls- und Vernetzungsfonds$$wt
000301010 680__ $$aElectrospray ionization (ESI) is a gentle, state-of-the-art technique to introduce biomolecular ions from solution into the gas phase and into vacuum, providing a solvent- and substrate- free environment. This allows studying the molecule in a well-defined, isolated state, where only intramolecular interactions have to be considered for describing structure and dynamics. The combination of an ESI source with advanced light sources such as synchrotrons, free- electron lasers and high harmonic generation sources allows for a novel and unique way to investigate structure and dynamics of gas-phase biomolecules. In particular, synchrotron and free-electron laser sources have the great advantage of superior photon brilliance, a wide photon energy range as well as polarization tunability. This enables systematic studies of energy and polarization dependent effects of ionization and dissociation processes. The following fundamental scientific complexes will be targeted within this project:  (i) Circular dichroism: Homochiral molecules have different absorption efficiencies for right or left circularly polarized light, the so-called circular dichroism (CD). Many CD studies aimed at discovering structural information on amino acids, proteins and DNA (building blocks) have been performed in the ultra-violet (UV) spectral region, but only a few CD studies enter the X-ray spectral range, where despite a very localized excitation, strong CD was observed. This local, site-selective probing with an X-ray pulse does not average the signal over the whole molecule, as is the case in the UV-visible absorption, and hence is a more selective tool to investigate structure-dependent dynamics in the molecule.  (ii) Radiation damage: Radiation therapy relies on ionizing radiation, yet, there is no consistent knowledge of the exact cascade of processes leading to radiation damage in a cell on atomic length and time scales. It is important to understand the details in the mechanisms of radiosensitizers, to increase the impact on tumors and to find non-toxic alternatives. To study the ultrafast processes of radiation damage on the molecular level, photoionization and photodissociation experiments will be performed on gas-phase nucleobases, amino acids and small oligonucleotides. These molecules will be explored in the pure as well as nanosolvated form. Moreover, metal ligands as well as radiosensitizers like cisplatin attached to oligonucleotides will be studied.  (iii) Ultrafast charge migration: Ultrafast charge transfer is believed to play an important role in biological energy conversion processes, such as light harvesting processes in plants. Pump-probe experiments of peptides will be performed to understand the fast charge migration processes in detail in terms of size, structure and time.
000301010 8564_ $$uhttp://hgf.desy.de/ivf/projekte/e208817/index_ger.html#hgf_e208818$$yProgrammorientierte Förderung von DESY
000301010 909CO $$ooai:juser.fz-juelich.de:811177$$pauthority$$pauthority:GRANT
000301010 909CO $$ooai:juser.fz-juelich.de:811177
000301010 980__ $$aG
000301010 980__ $$aAUTHORITY