Publications de Selma Schenkl | EPFL Graph Search

On the excitation wavelength dependence of the fluorescence of bacteriorhodopsin

Majed Chergui, Erwin Portuondo Campa, Goran Zgrablic, Stefan Haacke, Selma Schenkl

We present a systematic study of the time-integrated fluorescence of native bacteriorhodopsin, as a function of excitation wavelength across the visible absorption band. While the fluorescence max. is unaffected, the spectrum broadens on the high-energy si ...

Elsevier2007

Absorption spectroscopy of three-dimensional bacteriorhodopsin crystals at cryogenic temperatures: effects of altered hydration

Majed Chergui, Erwin Portuondo Campa, Selma Schenkl

A comparative study of absorption spectroscopy at 100 K has been performed on three-dimensional crystals of bacteriorhodopsin extd. from a lipidic cubic phase and on native purple membrane. A modified microspectrophotometer has been designed which yields a ...

2006

Insights into excited-state and isomerization dynamics of bacteriorhodopsin from ultrafast transient UV absorption

Majed Chergui, Frank van Mourik, Selma Schenkl

A visible-pump/UV-probe transient absorption is used to characterize the ultrafast dynamics of bacteriorhodopsin with 80-fs time resoln. We identify three spectral components in the 265- to 310-nm region, related to the all-trans retinal, tryptophan (Trp)- ...

National Academy of Sciences2006

Probing the ultrafast charge translocation of photoexcited retinal in bacteriorhodopsin

Majed Chergui, Frank van Mourik, Selma Schenkl

The ultrafast evolution of the electric field within bacteriorhodopsin was measured by monitoring the absorption changes of a tryptophan residue after excitation of retinal. The Trp absorption decreases within the first 200 femtoseconds and then recovers o ...

American Association for the Advancement of Science2005

Influence of the protein environment on spectroscopy and ultrafast dynamics of retinal in bacteriorhodopsin

Selma Schenkl

The environment is important for the exact course of a chemical reaction. As an example of the strong influence of the environment on the reaction, this work studies the isomerization reaction of the chromophore retinal in the binding pocket of the protein ...

EPFL2004