Description
General description
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 (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.
Application
Bacteriorhodopsin is of interest in the development of artificial retinas, optical associative processors, and three-dimensional memory storage devices.
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
Biochem/physiol Actions
A transmembrane retinylidine protein that functions as a proton pump driven by light energy in Holobacterium.
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.
Preparation Note
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.
