bacteriorhodopsin operates as a light/proton transfer pump which converts the light energy into a proton gradient. energy stored in the proton gradient can be used in a variety of ways. bacteriorhodopsin producing sources are some halobacterium species such as halobacterium sodomense and halobacterium salinarum which continue to grow in harsh and salt-saturated conditions. two types of red pigm...

bacteriorhodopsin operates as a light/proton transfer pump which converts the light energy into a proton gradient. energy stored in the proton gradient can be used in a variety of ways. bacteriorhodopsin producing sources are some halobacterium species such as halobacterium sodomense and halobacterium salinarum which continue to grow in harsh and salt-saturated conditions. two types of red pigm...

Halobacteria are extremely specialized organisms. They live exclusively in saturated solutions of common salt. The cell membrane of these bacteria exhibit insular regions which can be isolated by membrane fractionation. These regions consist of a lipid matrix containing bateriorhodopsin molecules in a hexagonal crystalline arrangement. Bacteriorhodopsin is a deep purple retinal-protein complex ...

The purple membrane is a two-dimensional crystalline lattice formed by bacteriorhodopsin and lipid molecules in the cytoplasmic membrane of Halobacterium salinarum. High-resolution structural studies, in conjunction with detailed knowledge of the lipid composition, make the purple membrane one of the best models for elucidating the forces that are responsible for the assembly and stability of i...

In the cell membrane of Halobacteria a photoreceptor protein, bacteriorhodopsin, forms a twodimensional hexagonal crystalline network within the lipid matrix [l-4] . This specialized domain of the membrane has been termed purple membrane [5,6]. Besides its attractiveness for bioenergetic studies, the purple membrane appears highly suited for studying the biogenesis of a membrane: Purple membran...

The purple membrane ofHalobacterium halobium contains a single protein known as bacteriorhodopsin, which is composed of 1 mol retinal]mol bacterio-opsin [ 1 ]. The organization of the protein within each purple membrane sheet is that of an exact 2-dimensional crystal. X-ray and electron diffraction data have revealed that the bacteriorhodopsin in purple membrane is arranged as trimeric units in...

Nanoscale electron transport through the purple membrane monolayer, a two-dimensional crystal lattice of the transmembrane protein bacteriorhodopsin, is studied by conductive atomic force microscopy. We demonstrate that the purple membrane exhibits nonresonant tunneling transport, with two characteristic tunneling regimes depending on the applied voltage (direct and Fowler-Nordheim). Our result...