The biopolymer bacteriorhodopsin in optical data processing

Bacteriorhodopsin (BR) from Halobacterium halobium [1] is embedded as a twodimensional crystalline lattice of BR-trimers in the lipid bilayer of the cell membrane [2]. BR consists of a single polypeptide chain of 248 amino acids which is arranged in seven transmembrane α-helices. A retinal molecule bound via a Schiff base to lysine-216 forms the chromophoric group [3]. Under illumination BR creates a proton gradient across the cell membrane which is used by a membrane-bound ATP-ase for ATP synthesis [4].