Photoreceptor dynamics in a simplified cell model

The cell interior is a complex environment characterised by crowding and confinement that can affect protein dynamics. The objective of this project is to unravel how cell conditions affect the kinetics and dynamics of functionally relevant structural changes triggered by light in photoreceptors. However, the experimental gap for going from a typical biophysical sample (i.e. a homogeneous protein solution) to a living cell is very large in terms of sample stability, light penetration, protein concentration etc. We have demonstrated in the past that time-resolved X-ray solution scattering can be successfully applied to monitor hemoglobin dynamics within intact erythrocytes, which are a simplified class of cells. The objective of the present proposal is to use the rapid hemolysis approach to trap photoreceptor proteins in erythrocytes. This strategy will represent a first step to move toward a realistic picture of out-of-equilibrium protein structural dynamics in real cells.