title: Electro-optical measurements on aqueous suspension of purple membrane from Halobacterium halobium.
abstract: The permanent dipole moment, polarizability, and the retinal angle of Halobacterium halobium purple membranes were determined at different pH values. All of the parameters have a maximum between pH 5 and 6. There is a reversal in the direction of the permanent dipole moment near pH 5. The value of permanent dipole moment was determined to be 60 D/protein at pH 6.6, and the value obtained for polarizability was 3 X 10(-28) Fm2/membrane fragment. The retinal angle of all-trans retinal was 0.8 degrees smaller than that of the 13-cis conformation.
mesh_terms: D001436:Bacteriorhodopsins / Q000502:physiology*; D002338:Carotenoids / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology; D002474:Cell-Free System; D002942:Circular Dichroism; D003624:Darkness; D006217:Halobacterium / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D008027:Light; D008280:Magnetics; D008564:Membrane Potentials; D012542:Scattering, Radiation
chemical_list: D002338:Carotenoids; D001436:Bacteriorhodopsins