LINEAR DICHROISM STUDIES OF THE ORIENTATION OF BACTERIORHODOPSIN IN LANGMUIR-BLODGETT MULTILAYER FILM
PM-SP-LB多层膜中BR分子的有序定向排列

Purple membrane(PM)-soybean phospholipid(SP) interface film were obtained by spreading onto a clear air-water interface a suspension of PM fragments in a SP n-hexane solution. PM-SP-Langmuir Blodgett(LB) multilayer film, deposited on quartz plate by vertical transfer method (vertical dipping), were studied by linear dichroism. The peak of visible absorption of the 60 layers LB film is about 574 nm, agreed with the film-forming soultiong, both peaks were red shifted with respect to the PM aqueous suspension The linear dichroism studies suggested that, bacteriorhodopsin has a preferred orientation with preferential ratio about 0.51 in the vertical dipping direction in addition to PM fragments lie on the multilayer plane. It also suggested that, the direction of orientation of the moment of the retinal chromophore with respect to the normal to the multilayer plane, is closed to the value in natural PM fragments.