Time-resolved spectroscopy meets time-resolved crystallography. Advances and challenges

The relationship between protein structure and function is fundamental to biology. Proteins are inherently dynamic, adopting multiple conformations that enable folding, catalysis, molecular recognition and signal transduction, yet capturing these processes across timescales from femtoseconds to hours remains a major challenge. Time-resolved spectroscopy probes excited states and tracks the kinetic evolution of intermediates generated in response to external stimuli, while time-resolved X-ray methods, including crystallography and solution scattering, provide atomic-resolution snapshots of structural changes and information on conformational dynamics. Because no single technique captures the full complexity of biomolecular dynamics, molecular dynamics simulations and quantum-mechanical calculations are essential for interpreting and integrating experimental findings.

This FEBS Workshop brings together researchers in time-resolved spectroscopy, time-resolved X-ray diffraction and scattering, and computational methods to present recent advances, discuss current challenges and strengthen interdisciplinary collaboration. It places particular emphasis on triggering strategies beyond light activation, including ligand mixing, photocage release, microfluidics and chemically triggered reactions, extending time-resolved studies to biological systems that are not intrinsically light-sensitive, and highlights instrumentation and methods developed at large-scale research facilities.

Topics: time-resolved spectroscopy; time-resolved serial crystallography at synchrotrons and XFELs; time-resolved X-ray solution scattering; time-resolved cryo-EM; sensory photoreceptors of optogenetic interest, membrane proteins, photosynthetic systems, UV damage, heme proteins and flavoproteins; triggering strategies including chromophore excitation, photo-uncaging, mixing and diffusion, temperature jumps and electric-field stimulation; computational biology (MD simulations, DFT, QM/MM); and software development for time-resolved spectroscopy and serial crystallography. This third edition builds on EMBO Dynamic Photobiology 2023 and FEBS Dynamic Photobiology 2025.