Bacteriorhodopsin (BR) is a retinal protein that functions as a light-driven proton pump. In this study, six novel mutants including K41E and D102K, were obtained to verify or rule out the possibility that residues Lys41 and Asp102 are determinants of the time order of proton release and uptake, because we found that the order was reversed in another retinal protein archaerhodopsin 4 (AR4), whi...

Photonic molecular devices have attracted tremendous interests because of their small size and light weight. The biologic protein bacteriorhodopsin (bR) and its derivatives are among the most promising candidates for potential applications in biomolecular photonics due to their unique properties [5]. In this investigation, film based on bR in Gelatin-polyvinil alcohol matrix of 0.001% (w/v) was...

Structural models of membrane proteins can be refined with sets of multiple orientation constraints derived from structural NMR studies of specifically labeled amino acids. The magic angle oriented sample spinning (MAOSS) NMR approach was used to determine a set of orientational constraints in bacteriorhodopsin (bR) in the purple membrane (PM). This method combines the benefits of magic angle s...

The decay rate of the Bacteriorhodopsin (BR) photocycle intermediate M412 and proton, the proton pump efficiency (H+/M412), the ratios of M412 to other intermediates and the rotational correlation time (tauc) in purple membrane (PM) fragments treated by the zwitterionic detergent 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS) with different concentrations were studied. The r...

Bacteriorhodopsin is probably the best understood proton pump so far and is considered to be a model system for proton translocating membrane proteins. The basis of a molecular description of proton translocation is set by having the luxury of six highly resolved structural models at hand. Details of the mechanism and reaction dynamics were elucidated by a whole variety of biophysical technique...

The light-driven proton pump bacteriorhodopsin (BR) from Halobacterium salinarum is tightly regulated by the [H(+)] gradient and transmembrane potential. BR exhibits optoelectric properties, since spectral changes during the photocycle are kinetically controlled by voltage, which predestines BR for optical storage or processing devices. BR mutants with prolonged lifetime of the blue-shifted M i...

The bulky and amphiphilic nature of tryptophan residues makes them particularly interesting components of proteins. In bacteriorhodopsin, four of the eight tryptophan residues are in the active site, forming parts of the retinal binding pocket. In this work, we use solid-state NMR to study the interactions of the tryptophan residues in wild-type bacteriorhodopsin, in the resting state, and in c...

The proton pump Bacteriorhodopsin (BR) undergoes repeated photocycles including reversible conformational changes upon visible light illumination. Exploiting the sensitivity of infrared (IR) spectra to conformation, we have determined reaction kinetic parameters conductive intermediate M for wild-type protein and its slow mutant D96N during photocycle. Time-resolved IR micro-spectroscopy using ...

Bacteriorhodopsin (BR) essentially free of native lipids has been prepared in a highly stable state. Purple membrane was solubilized in Triton X-100 and BR was purified by size exclusion chromatography using 3-[cholamidopropyl)dimethylammonio]-2-hydroxyl-1-propanesulfonic acid (CHAPSO) detergent at pH 5. Molar ratios of phospholipid/BR ranged from 0.4 to 0.05 corresponding to 94-98% phospholipi...

Bacteriorhodopsin (bR) has been biosynthetically prepared with lysine deuterated at its alpha carbon (C alpha--H). The labeled membranes containing bR were investigated by difference Fourier transform infrared (FTIR) spectroscopy. It has been derived from K/bR and M/bR difference spectra (K and M are photocycle intermediates) that several bands previously assigned to the retinal chromophore are...