Berlin 2005 – wissenschaftliches Programm
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MO: Molekülphysik
MO 15: Biomolecules II
MO 15.2: Vortrag
Freitag, 4. März 2005, 17:15–17:30, HU 2097
Structural identification of gas-phase biomolecules using IR spectroscopy — •Joost M. Bakker1,2, Isabelle Compagnon1, Gert von Helden2, Jos Oomens1, and Gerard Meijer2 — 1FOM Institute for Plasma Physics Rijnhuizen, Nieuwegein, The Netherlands — 2Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin
For biologically relevant molecules, the primary structure can nowadays be obtained in a rather routine fashion, making use of techniques such as mass spectrometry and electrophoresis. The secondary and higher orders structures, i.e. the three dimensional structure, of such systems are much harder to obtain, however. Since the secondary structure is a decisive factor in the biological function of the species, it is of great interest to study the fundamental interactions that determine the shape of the molecule. In gas-phase experiments the influences of a solvating medium are eliminated, so a careful study of these inter- and intramolecular interactions is possible.
Here, we present results of studies of gas-phase biomolecules using infrared (IR) ion-dip spectroscopy. Using this double-resonance technique, IR spectra of cold, well defined structural conformers can be measured. IR excitation of the molecules of interest is performed with mid-IR radiation (5–40 µm) produced by the Free-Electron Laser for Infrared eXperiments (FELIX) in Nieuwegein, the Netherlands, followed by UV ionization. Among systems that are studied are small tryptophan containing peptides, the gas-phase nucleobase pair guanine-cytosine and a model di-saccharide: lactose.