TY - JOUR T1 - Proton uptake mechanism in bacteriorhodopsin captured by serial synchrotron crystallography JF - bioRxiv DO - 10.1101/576629 SP - 576629 AU - Tobias Weinert AU - Petr Skopintsev AU - Daniel James AU - Florian Dworkowski AU - Ezequiel Panepucci AU - Demet Kekilli AU - Antonia Furrer AU - Steffen Brünle AU - Sandra Mous AU - Dmitry Ozerov AU - Przemyslaw Nogly AU - Meitian Wang AU - Jörg Standfuss Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/03/14/576629.abstract N2 - Conformational dynamics are essential for proteins to function. Here we describe how we adapted time-resolved serial crystallography developed at X-ray lasers to visualize protein motions using synchrotrons. We recorded the structural changes upon proton pumping in bacteriorhodopsin over 200 ms in time. The snapshot from the first 5 ms after photoactivation shows structural changes associated with proton release at comparable quality to previous X-ray laser experiments. From 10-15 ms onwards we observe large additional structural rearrangements up to 9 Å on the cytoplasmic side. Rotation of Leu93 and Phe219 opens a hydrophobic barrier leading to the formation of a water chain connecting the intracellular Asp96 with the retinal Schiff base. The formation of this proton wire recharges the membrane pump with a proton for the next cycle. ER -