Bacteriorhodopsin (BR570) bathochromic band shift in an external electric field.

In dry films of bacteriorhodopsin-containing purple membranes from Halobacterium halobium the external electric field (10(4) -- 10(5) V . cm-1) induces the appearance of a product spectrally close to the initial intermediate of bacteriorhodopsin (BR) photochromic cycle (bathoform, K). This result and also preliminary data of the electret-thermal analysis of the preparations suggest that the dielectric polarization in chromophore-protein-lipid complexes might be an essential step of the primary stabilization of light energy in photo-bioenergetic processes.