title: Induction of the blue form of bacteriorhodopsin by low concentrations of sodium dodecyl sulfate.
abstract: The effects produced on bacteriorhodopsin by low concentrations of several detergents have been studied by absorption and fourth-derivative spectrophotometry. Sodium dodecyl sulfate induces the appearance of the blue form of bacteriorhodopsin (lambda max = 600 nm) at pH values up to 7.0 in a reversible manner. The apparent pK of the purple-to-blue transition raised with increasing concentration of SDS. Of the other detergents tested, only sodium dodecyl-N-sarcosinate showed a slight red-shift of the absorption band to 580 nm, whereas sodium taurocholate, Triton X-100 and cetyltrimethylammonium bromide did not favour the appearance of the blue form. The effect of SDS was found to be consistent with a localized conformational change that moves away the counter-ion of the protonated Schiff base.
mesh_terms: D001436:Bacteriorhodopsins / Q000528:radiation effects; D002338:Carotenoids / Q000528:radiation effects; D006217:Halobacterium; D006863:Hydrogen-Ion Concentration; D008027:Light; D012967:Sodium Dodecyl Sulfate; D013057:Spectrum Analysis
chemical_list: D002338:Carotenoids; D012967:Sodium Dodecyl Sulfate; D001436:Bacteriorhodopsins