Membrane bound protein diffusion viewed by fluorescence recovery after bleaching experiments : models analysis

Diffusion processes in biological membranes are of interest to understand the macromolecular organisation and function of several molecules. Fluorescence Recovery After Photobleaching (FRAP) has been widely used as a method to analyse this processes using classical Brownian diffusion model. In the first part of this work, the analytical expression of the fluorescence recovery as a function of time has been established for anomalous diffusion due to long waiting times. Then, experimental fluorescence recoveries recorded in living cells on a membrane-bound protein have been analysed using three different models : normal Brownian diffusion, Brownian diffusion with an immobile fraction and anomalous diffusion due to long waiting times.