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MO: Molekülphysik

MO 10: Femtosekundenspektroskopie: Schwingungsdynamik

MO 10.5: Vortrag

Montag, 22. März 2004, 17:30–17:45, HS 315

Femtosecond Transient Vibrational Spectroscopy of Halorhodopsin — •Frank Peters¹, Joerg Tittor², Dieter Oesterhelt², and Rolf Diller³ — ¹Inst. f. Exp. Physik, FU Berlin, 14195 Berlin — ²MPI f. Biochemie, 82152 Martinsried — ³FB Physik, TU Kaiserslautern, 67663 Kaiserslautern

Femtosecond time resolved mid-infrared spectroscopy has been proven to be a powerful tool for investigating ultrafast vibrational dynamics in biological systems [1]. For the first time we have studied the all-trans to 13-cis chromophore isomerization in the light-driven chloride pump halorhodopsin (hR) with a time resolution of ca. 220 fs. The vibrational dynamics are dominated by two time constants, i.e. 1.8 and 7.5 ps. Implications regarding the chromophore reaction kinetics [2], especially the time constant of the 13-cis product formation are discussed. Concomitant protein dynamics are suggested by spectral changes on a similar time scale in the amide region. [1] J. Herbst, K. Heyne, R. Diller, Science 297(2002) 822-825. [2] T.Arlt, S. Schmidt, W. Zinth, U. Haupts, D. Oesterhelt, Chem. Phys. Letters 241 (1995) 559-565.