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Towards a molecular movie: Transient 2D-IR spectroscopy Peter Hamm

Towards a molecular movie: Transient 2D-IR spectroscopy Peter Hamm Physikalisch Chemisches Institut, Universität Zürich. Biosystems are Dynamical. Aquaporin-1 . B.L. de Groot and H. Grubmüller, Science 294, 2353-2357 (2001) http://www.mpibpc.gwdg.de/abteilungen/071/bgroot/gallery.html.

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Towards a molecular movie: Transient 2D-IR spectroscopy Peter Hamm

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  1. Towards a molecular movie: Transient 2D-IR spectroscopy Peter Hamm Physikalisch Chemisches Institut, Universität Zürich

  2. Biosystems are Dynamical Aquaporin-1 B.L. de Groot and H. Grubmüller, Science 294, 2353-2357 (2001) http://www.mpibpc.gwdg.de/abteilungen/071/bgroot/gallery.html

  3. Structure Sensitive Methods Scattering Methods (x-ray, electrons, neutrons) 2D-NMR + highest structure resolution power - works best in crystals + works best in solution + high structure resolution power - intrinsic time resolution very poor (1-100 ms) + intrinsic time resolution unlimited Time Resolved Scattering Methods 2D-IR +intrinsic time resolution fast (1 ps) - structure resolution power low but non-zero

  4. Coupled Vibrational States Linear Coupling: Site Basis Exciton Basis

  5. Linear Spectroscopy O O C O C N C N C C H H N C H H H H Frequency O H O R1 R3 C C N C C N C N C R2 O H H Frequency Strong coupling, homogeneous Weak coupling, heterogeneous R2 R3 R1

  6. 2D-IR Spectroscopy: Setup tp=100 fs Dw=200 cm-1 E=1 µJ Delay Spectrometer + 232 Element MCT Detector Array Fabry Perot Filter Sample

  7. 2D-IR Spectroscopy |2 |2‘ |1 |1‘ |0 |0‘

  8. 2D-IR Spectroscopy |20 |11‘ |02‘ |10 |01‘ |00‘

  9. 2D-IR Spectroscopy: Equilibrium • Conformation and distribution of conformations  Ultrafast equilibrium fluctuations Probe Frequency [cm-1] Woutersen et al. J. Phys. Chem. B, 104, 11316-11320 (2000) Woutersen et al., PNAS 98, 11254-11258 (2001) Woutersen et al. J. Chem. Phys.117, 6833-6840 (2002)

  10. Our Dream: Molecular Movie

  11. Photocleavable Peptide ? hn C. Kolano, K. Gomann, W. Sander, Eur. J. Org. Chem.2004, 20, 4167-4176.

  12. Photocleavable Peptide: IR spectrum Boc-Cys-Pro-Aib-Cys-OMe

  13. Equilibrium 2D Spectrum 1 ps t 2D-IR

  14. Equilibrium 2D Spectrum 1 ps t 2D-IR

  15. Equilibrium 2D Spectrum 1 ps t 2D-IR

  16. Transient 2D Spectroscopy: Setup IR Probe Fabry Perot Filter IR Pump Spectrometer + 232 Element MCT Detector Array Delay UV Switch Delay Sample Flow-Cell

  17. Transient 2D-IR Spectra 3-100 ps 1 ps t UVpump IRpump IRprobe 3 ps 25 ps 100 ps

  18. Nonequilibrium MD Simulations 1 ns Equilibrium Simulation (NVT): 120 ns Bondbreaking: Remove S-S Bond Non-Equilibrium Simulation (NVE): 600 ps • MD Package: Gromacs; Gromos Force Field 43a1 • Starting geometry: Based on low-resolution x-ray structure • Solvent box: Acetonitrile (1048 molecules)

  19. MD Simulations: Example Trajectories 3.0 Å

  20. MD Simulations: Average 6.1 Å 3.0 Å +s -s

  21. Transient 2D-IR Spectra Equilibrium 2D Transient 2D 100 ps C. Kolano, Nature 2006 in press

  22. Transient 2D-IR Spectra Equilibrium 2D Transient 2D 100 ps

  23. Transient 2D-IR Spectra Equilibrium 2D Transient 2D 100 ps

  24. And Finally: The Movie

  25. Conclusion Transient 2D-IR spectroscopy combines picosecond time resolution with microscopic structural information Transient 2D-IR reveals new insight into fast structural dynamics of peptides, that cannot be obtained otherwise.  An ultrafast molecular movie of the 3D- structure conceivable (in connection with isotope labeling)

  26. Outlook: Isotope Labelling a-Helix Folding 13C=O 13C=18O 13C=O 13C=18O hn

  27. Acknowledgement • University Zürich University Munich • - Dr. Christoph Kolano - Prof. Wolfgang Zinth • Dr. Jens Bredenbeck • Dr. Jan Helbing University Bochum • Mariusz Kozinski - Dr. Christoph Kolano • Valentina Cervetto - Prof. Wolfram Sander • Harald Bregy • Ellen Backus Max Planck Institut, Martinsried • Virgiliu Botan - Dr. Christian Renner • - Prof. Luis Moroder • Max Born Institut, Berlin • Dr. Sander Woutersen University of Toronto • Prof. Thomas Elsaesser- Prof. Andrew Woolley • University FrankfurtFinancial Support • Prof. Josef Wachtveitl - Universität Zürich • Prof. Gerhards Stock - Swiss Science Foundation • - Deutsche Forschungsgemeinschaft

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