Berlin 2014 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 24: Biomolecules 2
MO 24.1: Vortrag
Freitag, 21. März 2014, 14:00–14:15, BEBEL SR144
IRMPD spectra of metal-lumichrome ionic complexes — •Pablo Nieto1, Alan Günther1, Sophie Seidenbecher1, Judith Langer1, Giel Berden2, Jos Oomens2, and Otto Dopfer1 — 1Institut für Optik und Atomare Physik Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin, Germany — 2Radboud University Nijmengen Institute for Molecules and Materials, FELIX facility, Toernooiveld 7, 6525 ED Nijmengen, The Netherlands
Flavins are a fundamental class of biomolecules with a lumichrome (LC) chromophore. This family of molecules is involved in many important biological processes. To understand these phenomena at the molecular level, spectroscopic studies of isolated flavins and their complexes are required. We report IRMPD spectra of mass selected Meq+-LC (Meq+= Li+, Na+, K+, Rb+, Cs+, Mg2+ and Ag+) ionic complexes in the fingerprint range (800-1900 cm−1) recorded in a FT-ICR-MS ion trap coupled to the free electron laser FELIX. In the liquid phase, flavins preferently bind to positions at N5 and O4 [2]. In contrast, the additional O2 binding site was identified in our experiments. Furthermore, the spectra for Li+ and Ag+ are very similar, suggesting that both ions have comparable binding energies to LC. Finally, Mg2+ ions form strongly-bound Mg2+-(LC)2 complexes in a T-shaped structure. The large IRMPD linewidth (>15 cm−1) due to the ion temperature (300 K) poses a limitation to these experiments. This limitation will be overcome with our new apparatus equipped with an ESI source and a cryogenic 22-pole ion trap (4 K) where single photon absorption spectroscopy will be carried out.