VlsE-FRET a destabilized protein in cell

The understanding of protein folding dynamics inside cells is crucial for the development of new therapies against protein folding diseases. Also, several processes in the cell can be controlled based on the protein folding stability, which can regulate protein production, variation, post-translational modifications and degradation. Fast Relaxation Imaging (FReI) is a new fluorescence method that allows us to study protein dynamics in cells. Using FReI and a constructed FRET pair protein of the Variable Lyme Disease Surface Antigen E (VlsE), we have carried out experiments that show this construct to be destabilized inside cells. VlsE-FRET has lower T_m and slower unfolding kinetics in cell. VlsE has different regions that undergo antigenic variation in order to evade the immune system of the host. Probably, the VlsE-FRET destabilization in cell is part of the trigger mechanism for the extensive genetic and antigenic variation that allows VlsE to evolve.