The cytoplasmic surface topography of purple membranes imaged by the atomic force microscope depends mainly on the force applied to the stylus. Imaged at forces of 300 pN, individual bacteriorhodopsin molecules reveal two domains. The resulting donut-shaped trimers reversibly transform into structures exhibiting three prominent protrusions when scanned at 100 pN. In parallel, the height of the ...

The folding mechanism of integral membrane proteins has eluded detailed study, largely as a result of the inherent difficulties in folding these proteins in vitro. The seven-transmembrane helical protein bacteriorhodopsin has, however, allowed major advances to be made, not just on the folding of this particular protein, but also on the factors governing folding of transmembrane alpha-helical p...

The transmission properties of some bacteriorhodopsin-film spatial light modulators are uniquely suited to allow nonlinear optical image-processing operations to be applied to images with multiplicative noise characteristics. A logarithmic amplitude-transmission characteristic of the film permits the conversion of multiplicative noise to additive noise, which may then be linearly filtered out i...

Next-generation communication networks require > Tbit/s single-channel data transfer and processing with sub-picosecond switches routers at network nodes. Materials enabling ultrafast all-optical switching have high potential to solve the speed limitations of current optoelectronic circuits. Chromoproteins exhibit a large light-controlled refractive index change alleviating driving energy requi...

Bacteriorhodopsin is a heptahelical membrane protein that can be refolded to the native state following denaturation. To analyze the in vitro folding process with independent structural domains, eight fragments comprising two (AB, FG), three (AC, EG), four (AD, DG) or five (AE, CG) of the transmembrane segments were produced by expression in Escherichia coli. The polypeptides were purified to h...

Photochemical hole burning has been observed at 1.5 K in bacteriorhodopsin (bR) and bovine rhodopsin at wavelengths spanning their lowest energy electronic absorption bands. Hole widths were -2500 cm-' full width at half-maximum (fwhm) in bacteriorhodopsin and -2400 cm-' fwhm in rhodopsin. The positions of the hole minima were insensitive to bum wavelength, indicating that minimal site selectio...

The object of this study is the processes interaction fragments purple membranes with certain chemicals, which affect photochromic properties bacteriorhodopsin films. This paper considers possibility modifying films by changing their chemical composition, will make it possible to use such protect information. For purpose, has been determined optical are most important for its in field informati...

Abstract Archaea are prokaryotic organisms with highly interesting physiological features. They have also shown potential for the production of biotechnological compounds. Today, commercially available products archaea bacterioruberin, squalene, bacteriorhodopsin, and lipids — all which produced by utilizing halophilic archaea. Other include carotenoids, bioplastics, molecular hydrogen, methane...