Hannover 2010 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 14: Femtosecond Spectroscopy II
MO 14.1: Hauptvortrag
Mittwoch, 10. März 2010, 14:00–14:30, F 102
Ultrafast Conformational Dynamics of Azopeptides — •Josef Wachtveitl1, Lisa Lorenz1, Karsten Neumann1, Heike Staudt1, Ulrike Kusebauch2, and Luis Moroder2 — 1Institute of Physical and Theoretical Chemistry, Institute of Biophysics, Johann Wolfgang Goethe-University, 60438 Frankfurt/Main — 2Max-Planck-Institute of Biochemistry, 82152 Martinsried, Germany
Azobenzene derivatives have been used as backbone constituents or side-chain clamps to photocontrol in reversible manner conformational states of model peptides [1]. Because of the ultrafast isomerization (within picoseconds), this chromophore allows spectroscopic monitoring of the fast kinetics of folding/unfolding of model peptides with ordered secondary structure motifs such as β-turns, α-helices and most recently even of β-hairpins. Aim of the present work is to gain new insights into the kinetics of assembly of tertiary structure motifs such as the collagen triple helix. For this purpose model peptides were conformationally restricted with a suitable azobenzene clamp in the trans-isomeric state, which upon photoisomerization provokes unfolding of the triple helix [2]. Upon excitation of the ππ∗-transition, trans-cis isomerisation of a specially designed collagen-sample and its azobenzene clamp is examined by time resolved spectroscopy in the visible and infrared spectral region. The functionality of the azobenzene clamp is conserved upon binding, making it a promising tool for the investigation of tertiary structure formation.
[1] Wachtveitl, J., Spörlein, S., Satzger, H., Fonrobert, B., Renner, C., Behrendt, R., Oesterhelt, D., Moroder, L. and Zinth, W., Ultrafast Conformational Dynamics in Cyclic Azobenzene Peptides of Increased Flexibility, Biophys. J., 86, 2350 (2004)
[2] Kusebauch, U., Cadamuro, S.A., Musiol, H.-J., Lenz, M. U., Wachtveitl, J., Moroder, L. and Renner, C., Photocontrolled Folding and Unfolding of a Collagen Triple Helix, Angew. Chem. Int. Ed., 45 7015-7018 (2006)