PHOTOINDUCED CHANGES IN THE MONOLAYERS OF BACTERIORHODOPSIN STUDIED BY THE BREWSTER-ANGLE REFLECTION TECHNIQUE

Photosensitive properties of the membrane protein pump - bacteriorhodo psin (BR) were investigated directly in monolayers at the gas/liquid i nterface by the use of recently developed Brewster angle reflection te chnique. The thickness of BR monolayer at the interface was estimated by that method as 4.5 nm that was equal to the lipid bilayer. Thus, su ch monolayers can be considered as the adequate model of the biomembra nes. The reversible changes of the Brewster angle reflection signal we re found during the illumination (570 nm)/dark relaxation (or illumina tion with 420 nm) cycle. These data coincide with the reversible chang es of the protein structure at the photoactivation and will be importa nt for the design of molecular devices.