Bacteriorhodopsin from Halobacterium salinarum

Bacteriorhodopsin (BR) is a covalent complex comprising bacterioopsin protein and retinal cofactor in the equimolar ratio. It corresponds to the molecular weight of 27kDa. BR belongs to the retinylidene class of proteins. It is a seven-membrane helical protein that acts as a photon-driven pump. BR can be used in studies of the folding and kenetics of β-helical proteins.

Bacteriorhodopsin is the prototypical "seven-helix" transmembrane protein (with seven α-helical domains), whose study led to advances in understanding G protein-coupled receptors (GPCRs). In Halobacteria, it acts as a light-harvesting protein, producing a proton gradient across the cell wall that is then used to drive biosynthetic processes.

Bacteriorhodopsin from Halobacterium salinarum has been used:

• in generation of droplet lipid bilayer
• as a standard in quadrupole time-of-flight (QTOF) mass spectroscopy (MS)
• in the generation of protein-detergent complex and micelles for dynamic light scattering studies

Bacteriorhodopsin is of interest in the development of artificial retinas, optical associative processors, and three-dimensional memory storage devices.

Bacteriorhodopsin (BR) from Halobacterium salinarum acts as a proton-driven pump. BR can be used in studies of the folding and kinetics of α-helical proteins. It is thermally stable and exhibits high photoelectric and photochemical efficiency. BR exists as trimer in a hexagonal lattice. Its photocycle intermediates are exploited in bioelectronics majorly in photoelectric and photochemical applications.

A transmembrane retinylidine protein that functions as a proton pump driven by light energy in Holobacterium.

Aqueous suspensions may be sonicated to achieve the desired homogeneity and may be stored for a short time at a temperature of 2-8 °C or at a temperature of -20 °C without time limitation.

Wild-type bacteriorhodopsin is isolated from Halobacterium salinarum strain S9 as purple membranes.