Science@FELS

Session

Biology

22 Sept 2026, 11:00

Auditorium (WHGA/001) (Paul Scherrer Institut)

Conveners

Biology

• Camila Bacellar (PSI - Paul Scherrer Institut)

Biology

• John Henry Beale (PSI - Paul Scherrer Institut)

105. "Fighting quantum yield: two challenging SFX targets"

Thomas Lane (DESY)

22/09/2026, 11:00

Tutorial

46. Impact of Electron Trapping on Coulomb Explosion Imaging of Proteins at XFELs

Kalyani Chordiya (University of Hamburg)

22/09/2026, 11:40

AMO Physics

Oral

Understanding the ultrafast response of proteins and large biomolecules to intense X-ray pulses is essential for advancing their structural and dynamical studies. A critical question for larger systems (>1000 atoms) is whether a complete Coulomb explosion can develop before electron trapping suppresses it. In this work, we examine the competitive dynamics between Coulomb explosion and electron...

7. Crystal optics selects weak response of ultrafast crystallography

Jasper van Thor (Imperial College London)

22/09/2026, 11:55

Invited

Time-resolved X-ray crystallography requires intense, short laser pulses to achieve ultrafast time resolution. It is currently not known to what extent double optical excitation as a result of intense laser illumination, can contribute to measured signals. We present a separation of weak and strong response from pump-probe data of photoactive yellow protein crystals collected at a single...

28. Analysis of diffraction data from time-resolved experiments suggests incoherent addition of populations of states

Dusan Turk (Jozef Stefan Institute)

22/09/2026, 12:20

Oral

Analysis of diffraction data from time-resolved experiments suggests
incoherent addition of populations of states

Current refinement of crystal structures with excited-state
populations commonly relies on extrapolated data sets (Schmidt et al.,
2003; De Zitter et al., 2022). These are derived from differences
between diffraction data collected from crystals containing mixed
ground-...

40. Ultrafast X-ray biological imaging without crystals

Filipe Maia (Uppsala University)

22/09/2026, 12:35

Invited

The quest to image single molecules played a crucial role in the development of X-ray free-electron lasers (XFELs). The ultra-bright, ultrafast pulses of XFELs enable the recording of a particle’s diffraction pattern before radiation damage destroys it—a concept first proposed by Neutze et al. ([Nature, 2000][1]) and experimentally demonstrated at FLASH over a decade ago ([Chapman et al.,...

103. Integrated time-resolved structural biology approaches to visualize photoreceptor proteins at work

Martin Weik (IBS)

23/09/2026, 08:30

Tutorial

Photoreceptor proteins utilise the absorption of light to elicit a biological response in a variety of processes, including vision, circadian rhythms and plant development. The focus of current research is the understanding of how the initial photochemical events at the receptor's chromophore funnel through space and time into the desired photobiological event.
In order to visualise...

89. Sub-picosecond Low-Barrier Hydrogen Bond Collapse Preceding Proton Transfer Reaction in a Light-Driven Ion Pump

Kirill Kovalev (European Molecular Biology Laboratory)

23/09/2026, 09:10

Invited

Abstract:
Proton transfer underlies enzymatic catalysis, ion transport, and energy conversion across biology, often involving short, strong H-bonds in which the proton is delocalized between two functional groups. Such low-barrier H-bonds (LBHBs) have been shown in protein active sites, but their dynamics are difficult to capture in this environment because LBHBs unfold on ultrafast...

47. Sample delivery for structural biology at the European XFEL

Katerina Dörner (European XFEL)

23/09/2026, 09:35

Oral

The European XFEL (EuXFEL) facilitates high-resolution structural studies of biological systems at MHz pulse repetition rates. Serial femtosecond crystallography (SFX) - next to scattering and imaging techniques - is the most common approach. Time-resolved structural studies are enabled with optical pump-probe or mixing experiments. To accommodate the MHz repetition rate, sample delivery...

91. Sulfur Photochemistry in Human γD-Crystallin

Briony Yorke (School of Chemistry)

23/09/2026, 09:50

Invited

The eye lens has evolved to retain transparency throughout the organismal lifespan in the absence of cellular regeneration. The crystallin proteins that constitute the lens remain folded and soluble for more than 50 years in humans despite daily exposure to ultraviolet (UV) radiation. Human γD-crystallin (HGD) is one of the principal structural proteins of the lens. Long regarded as a passive...

54. Time-resolved GPCR photopharmacology at next-generation X-ray sources

Jörg Standfuss (PSI - Paul Scherrer Institut)

23/09/2026, 10:15

Oral

Jörg Standfuss

representing collaborators at PSI Center for Life Sciences, PSI Center for Photon Science, LeadXpro AG, Institute for Advanced Chemistry of Catalonia, Stanford Cancer Institute, SLAC National Accelerator Laboratory, and University of Zurich

Abstract:
The advent of next-generation synchrotrons and X-ray free-electron lasers enables time-resolved structural biology at...