Speaker
Description
Providing detailed experimental insights into how proteins change over time and to relate these structural changes to biological function remains one of the major challenges in structural biology. Next generation X-ray sources including diffraction-limited synchrotrons and X-ray Free Electron Lasers offer exciting new opportunities to study protein dynamics by time-resolved pump-probe crystallography.
In the last few years, my group has demonstrated the use of high-viscosity injectors to increase sample efficiency in time-resolved measurements${^1}$. This allowed us and our collaborators to assemble over 40 structural snapshots of the light-driven proton pump bacteriorhodopsin. In a wide temporal window, we cover the light-induced isomerization of retinal within the first few hundred femtoseconds${^2}$, the following proton release steps within microseconds${^3}$ and the proton uptake reaction in the early milliseconds${^4}$. Together this provides the most complete molecular view of a membrane pump in action and acts as a template how to approach studies on proteins with increasing complexity. As a first step in this direction, we and our collaborators concluded piloting time-resolved crystallographic measurements at the Swiss Light Source and the Swiss X-ray Free Electron Laser to resolved the structural changes within light-driven sodium pumping${^5}$ and chloride pumping rhodopsins${^7}$. In our latest work we aimed at increasing the number of proteins that can be studied using pump-probe techniques through the use of synthetic photoaffinity switches${^6}$. The overarching goal is to map the structural dynamics of protein-ligand interactions in a series of proteins used in optogenetics and photopharmacology.
References:
- Nogly, P. et al. Lipidic cubic phase injector is a viable crystal delivery system for time-resolved serial crystallography. Nat Commun 7, 12314 (2016).
- Nogly, P. et al. Retinal isomerization in bacteriorhodopsin captured by a femtosecond x-ray laser. Science 361 (2018).
- Nango, E. et al. A three-dimensional movie of structural changes in bacteriorhodopsin. Science 354, 1552-1557 (2016).
- Weinert, T. et al. Proton uptake mechanism in bacteriorhodopsin captured by serial synchrotron crystallography. Science 365, 61-65 (2019).
- Skopintsev,P. et al. Femtosecond-to-millisecond structural changes in a
light-driven sodium pump. Nature (2020). - Mous, S. et al. Dynamics and mechanism of a light-driven chloride pump. Science, eabj6663 (2022).
- Wranik, M. et al., Molecular snapshots of drug release from tubulin. bioRxiv, https://doi.org/10.1101/2022.02.17.480857 (2022)
| Would you like to participate in the Poster Prize competition? | No |
|---|
