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Updated: Feb 9, 2026

Femtosecond Laser Filaments for Use in Sub-Diffraction-Limited Imaging and Remote Sensing
Published on: April 25, 2019
Retinal isomerization in bacteriorhodopsin captured by a femtosecond x-ray laser
Przemyslaw Nogly1, Tobias Weinert1,2, Daniel James1
1Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland.
Abstract:
Ultrafast isomerization of retinal is the primary step in photoresponsive biological functions including vision in humans and ion transport across bacterial membranes. We used an x-ray laser to study the subpicosecond structural dynamics of retinal isomerization in the light-driven proton pump bacteriorhodopsin. A series of structural snapshots with near-atomic spatial resolution and temporal resolution in the femtosecond regime show how the excited all-trans retinal samples conformational states within the protein binding pocket before passing through a twisted geometry and emerging in the 13-cis conformation. Our findings suggest ultrafast collective motions of aspartic acid residues and functional water molecules in the proximity of the retinal Schiff base as a key facet of this stereoselective and efficient photochemical reaction.
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