Optical Bioimaging Laboratory

One of the specially selected α-helices (K or E) serves as a label for the target protein, and the other is placed on a genetically encoded fluorescent protein. Due to the reversible interaction of K and E-helices, the target protein structure is stained, and the continuous exchange of fluorescent proteins in the complex increases the resistance to photobleaching by an order of magnitude. The small size of the labels (only 2-3 kDa) allows us to preserve the native dynamics of the studied proteins. In addition, this method makes it possible to observe proteins almost immediately after their synthesis. The most interesting was the use of K/E-helices for Protein-PAINT, an ultra–high-resolution localization microscopy based on reversible interacting labels. The continuous exchange of fluorescent proteins between the target cell structure and the cytoplasmic pool ensures a consistently high tagging density even with prolonged shooting. With the help of K/E-spirals, it was possible for the first time to implement the concept of Protein-PAINT nanoscopy using only genetically encoded reporters.

Creation of tags based on ligand-binding proteins and synthetic fluorogens for use in nanoscopy of living cells, as well as as modulated FRET acceptors for the study of protein-protein interactions.