Optical control of the primary step of photoisomerization of the retinal molecule in bacteriorhodopsin from the all-trans to the 13-cis state was demonstrated under weak field conditions (where only 1 of 300 retinal molecules absorbs a photon during the excitation cycle) that are relevant to understanding biological processes. By modulating the phases and amplitudes of the spectral components i...

New techniques for measuring the diffusion of proteins in cell membranes have recently been reported [l-7] . Such measurements should in principle test to what extent proteins are freely floating in the fluid lipid bilayer, as envisaged in currently popular concepts of membrane structure [8]. They may also provide a method of investigating structural features of membranes which restrict or prev...

bacteriorhodopsin (br) is the light harvesting and photoactive proton pump found in the membrane of a salt marsh bacteria. this protein has significant potential to use in optical computing and memory devices due to unique intrinsic physical properties of photo and bioelectric. all these features make br one of the most promising protein candidates in protein memories. protein memory is a kind ...

We describe an original activity assay for membrane transport that uses the proton motive force-dependent efflux pump MexAB from Pseudomonas aeruginosa. This pump is co-reconstituted into proteoliposomes together with bacteriorhodopsin (BR), a light-activated proton pump. In this system, upon illumination with visible light, the photo-induced proton gradient created by the BR is shown to be cou...

This review deals with the role of carboxylic amino acids in the proton transport activity of bacteriorhodopsin. The main focus is on the infrared data, which allow direct monitoring of the protonation/deprotonation of specific residues dur ing the proton movement in the course of the photocycle. Additional attention is paid to the potential use of carboxylic acids in proteins as internal senso...