Berlin 2018 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 82: Membranes and Vesicles II (joint session BP/CPP)

CPP 82.2: Vortrag

Freitag, 16. März 2018, 09:45–10:00, H 2013

Vesicle adhesion and fusion studied by small-angle x-ray scattering — •Karlo Komorowski¹, Annalena Salditt¹, Yihui Xu¹, Halenur Yavuz², Martha Brennich³, Reinhard Jahn², and Tim Salditt¹ — ¹Institut für Röntgenphysik, Georg-August-Universität Göttingen, Göttingen, Germany — ²Department of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany — ³European Molecular Biology Laboratory, Grenoble, France

Membrane fusion takes place in numerous physiological processes on the cellular and subcellular level as in the case of synaptic neurotransmission. The merger of two membranes generally involves a highly complex interplay on the molecular level among lipids, membrane fusion proteins, ions of the aqueous environment and water molecules. We aim at the structure of intermediate states of a vesicle and membrane fusion pathway. A main emphasis is laid on adhered vesicles. Recent observations indicate that such a docking state, showing two flattened membranes in close proximity, plays a role in vesicle fusion. For this purpose, we have studied adhesion and fusion of lipid vesicles induced by CaCl₂/MgCl₂, and show that a stable adhesion state can be induced under certain conditions. The bilayer structure and the inter-bilayer distance between adhered vesicles was analyzed by small-angle x-ray scattering (SAXS). From the obtained structural parameters we aim at an understanding of inter-membrane potentials in adhesion and in fusion. Finally, we have studied structural dynamics of lipid vesicle fusion using time-resolved SAXS techniques, and show that intermediate states can be distinguished over time.