TR-USAXS/SAXS investigation of Myelin Basic Protein liquid-liquid phase separation kinetics

Liquid-liquid phase separation (LLPS) of intrinsically disordered proteins has attracted a wide attention in the biological and biophysical community. We suggest to investigate the kinetics of the LLPS of the intrinsically disordered myelin basic protein (MBP) and connected structural changes of the protein using time-resolved (TR) USAXS/ SAXS at ID02 with the stopped flow technique. MBP is essential for the integrity of myelin sheaths ensuring flawless neuronal signal propagation and it is assumed that LLPS is necessary for its physiological function. We propose to use 3 detector distances to investigate a q-range of 1∙10^-3 - 5∙10^0 1/nm in order to observe internal protein structure, droplet nucleation and droplet growth evolution. Our proposed experiments take 60 hours of pure X-ray beamtime, so we believe that 3 days of beamtime are necessary considering extra time required to set up the device, do cleaning, test-shots, find suitable exposure times and radiation intensities.