Yamazaki Lab develops new imaging methods to investigate structures, functions, and dynamics of biomembranes, proteins, and cells, and reveal elementary processes of the dynamics of these biomolecular super-assemblies using the various imaging methods. Based on these experimental results, we elucidate physical laws and design principles of living systems.
(1) Developement of the single GUV method
To investigate interactions of substances such as peptides/proteins with biomembranes and dynamics of biomembranes, we have developed a novel method, the single GUV method, using giant unilamellar vesicles (GUVs) of biomembranes with a diameter of ≥ 10 mm. The single GUV method can visualize functions and dynamics of biomembranes and allows us to obtain rate constants of their elementary processes by their statistical analysis. Using this method we investigate the elementary processes and mechanisms of various functions and dynamics of biomembranes.
(2) Antimicrobial peptides (AMPs), Cell-penetrating peptides (CPPs), and Pore-forming toxins (PFTs)
We investigate pore formation induced by AMPs and PFTs and translocation of CPPs across lipid bilayers using the single GUV method. We also investigate the interaction of AMPs and CPPs with living bacterial cells and eukaryotic cells.
(3) Effect of membrane tension on function and dynamics of biomembranes.
External forces and osmotic pressure induce membrane tension in plasma membranes of cells and lipid bilayers of vesicles. Especially tension-induced pore formation and effect of tension on translocation are investigated.
(4) Stability of cubic phase of biomembranes and their structural transformation such as phase transition
We also investigate structural changes in nanometer scale and phase transitions of biomembranes. We found that electrostatic interactions induced phase transitions between cubic and liquid-crystalline phases of biomembranes, and investigate their mechanisms.