RHODOPSIN-PHOSPHOLIPID INTERACTION IN DETERGENT AND IN THE DISK |
| |
Authors: | Atsushi Ikai Eriko Tamura Masaaki Nishigai |
| |
Affiliation: | Department of Biophysics and Biochemistry, Faculty of Science, The University of Tokyo, Hongo, Tokyo, Japan 113 |
| |
Abstract: | Abstract— Solubilization of cattle disk membrane in deoxycholate shifted the fluorescence emission maximum from 324 to 331 nm without changing the intensity. Tryptophyl residues are probably located at the hydrophobic interface between rhodopsin and phospholipid. Depletion of deoxycholate concentration from the solubilized disk by Sephacryl 200 column chromatography produced rhodopsin-phospholipid complexes with different characteristics that are the intermediate stages of membrane formation from homogeneous molecular solution. Association of rhodopsin takes place in a two-dimensional way even in the appreciably low content of phospholipid. Sedimentation velocity studies showed that reassociation of lipid and rhodopsin occurs in 0.2% deoxycholate as well as in 0.05% sodium dodecylsulfate. By using Sephacryl column we can now prepare, within 60 min, the rhodopsin-lipid complex that can form large vesicles in response to the addition of MgCl2 without dialysis. This type of lipoprotein complex will be useful to the study of the mechanism of the two dimensional membrane formation. |
| |
Keywords: | |
|
|