Reconstitution of delipidated bacteriorhodopsin with endogenous polar lipids.

摘要: Delipidated bacteriorhodopsin has been reconstituted with endogenous polar lipids from Halobacterium halobium. The vesicle (diameter, 250-500 A) formed are very stable, relatively homogeneous in and lipid content, almost optically clear; a minor turbid fraction can be separated by gel filtration. Bacteriorhodopsin the vesicles an inside out orientation and, on illumination, translocates protons efficiently medium to interior of presence ionophore valinomycin. In absence latter, both rate extent light-dependent proton uptake decreased 3-6- 5-15-fold, respectively, depending salt assay medium. Both stimulation valinomycin proton-translocating activity higher NaCl than KCl. these as purple membrane, undergoes light adaptation indicated red shift (7-8 nm) absorption maximum. At low pH, maximum protein shows 50-nm shift, possibly due protonation ionizable group which interacts chromophore. latter appears accessible only external