Serial macromolecular crystallography has become a popular technique to study structural dynamics of biological samples at room temperature. However, the experiments remain complex and are often challenging for broader applications. The long-standing collaboration between ESRF and EMBL have developed the world’s first synchrotron beamline specifically designed for this application, the new ID29. This beamline features high-brilliance and highrepetition- rate microsecond X-ray pulses with innovative beam characteristics, and versatile sample environment for the structure determination of biological samples at physiological condition.
Thanks to the upgrade of the ESRF to a high-energy 4th generation Extremely Brilliant synchrotron Source (ESRF-EBS), ID29 can deliver a flux density (1014 ph/s/μm2) 3 order of magnitudes higher than 3rd generation synchrotron microfocus beamlines, reducing the exposure time down to a few microseconds. As such, the authors have developed a novel technique which they have termed “serial microsecond crystallography (SμX)”. The authors demonstrated sample environment versatility by measuring SμX datasets from various sample delivery methods – fixed target (foils and chips) and three different types of high-viscosity injectors. The use of a slightly polychromatic beam produces high quality “fuller” Bragg reflections even for a less redundant dataset, which combined with the high repetition rate, make it possible to achieve high quality structural information with exceptionally low sample-consumption.
One of the major findings, achieved in collaboration with Dr. Guillaume Lebon at the Institut de Génomique Fonctionnelle (IGF) in Montpellier, reveals how SμX efficiently allows to visualize the binding of a pharmaceutical drug, Istradefylline, to a human integral membrane receptor with only a few thousands of diffraction images. Thus, SμX with further automation will attract industrial users at the ESRF for pharmaceutical research.
Additionally, the results also showed that, despite the high deposited dose, the structures obtained via SμX do not present any evident sign of radiation damage. In conclusion, the publication proves that pioneering SμX developed at ID29, bridges standard structural biology beamlines and XFELs. The concept design of ID29, together with advanced technology, is already inspiring other future beamlines worldwide and opens a new frontier of time-resolved SμX at synchrotrons.
J. Orlans (ESRF), S.L. Rose (ESRF), S. Basu (EMBL) and D. de Sanctis (ESRF)
Orlans, Rose, and Ferguson et al., (2025), Commun Chem., 8 (6).
