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BP: Fachverband Biologische Physik
BP 9: Bioimaging
BP 9.4: Talk
Tuesday, September 6, 2022, 10:15–10:30, H16
Pool formation of synaptic vesicles by synapsin investigated by X-ray diffraction and cryo-EM — •Jette Alfken1, Charlotte Neuhaus1, Moritz Stammer1, Marcelo Ganzella3, Arsen Petrovic4, Rubén Fernández-Busnadiego4, Reinhard Jahn3, Dragomir Milovanovic2, and Tim Salditt1 — 1Georg-August-Universität, Institute for X-ray Physics, 37077 Göttingen — 2Laboratory of Molecular Neuroscience, German Center for Neurodegenerative Diseases (DZNE), 10117 Berlin — 3Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany — 4Institute of Neuropathology, University Medical Center Göttingen, 37099 Göttingen
Synaptic vesicles (SVs) are organized in dense pools close to the synaptic membrane. A key protein for this structural arrangement within the synapse is synapsin, which forms droplets containing SVs, due to liquid-liquid phase separation. To study the structure and interactions underlying pool formation in a controlled in vitro model, we have investigated phases made of SVs purified from rat brain and varied synapsin concentration. We have studied the pools by two complementary techniques: cryo-EM yielding the 3D structural arrangement of the adhering vesicles in pools at resolution of a few nanometers in the vitrified state, and solution SAXS under varied buffer conditions and concentrations. In addition, the pools were studied for comparison in a controlled system consisting of artificially prepared lipid vesicles and synapsin. We report these experiments and preliminary results (data analysis still ongoing).