We develop 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.　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 μm (Fig. 1). 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 (Fig.2). Using this method we investigate the elementary processes and mechanisms of various functions and dynamics of biomembranes. 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 (Fig.3).

Awai lab is working on physiological functions of lipids in the photosynthetic membranes and production of useful compounds, using cyanobacteria (Fig. 4) as a model system.

Oka lab researches on phase transitions of lipid membranes (Fig.5) and structural changes of proteins (Fig.6) using X-ray diffraction/scattering methods, and also develops related methods, e.g. alignment methods of lipid membranes and X-ray measurement methods.