A possible role of rhodopsin in maintaining bilayer structure in the photoreceptor membrane.
31P-NMR measurements demonstrate that at 37 degrees C, independent of the photolytic state of the photopigment rhodopsin, the lipids in the photo-receptormembrane are almost exclusively organised in a bilayer. In strong contrast, the 31P-NMR spectra of the extracted lipids are characteristic for the hexagonal HII phase and an isotropic phase. The isotropic phase is characterised by freeze-fracture electron microscopy as particles and pits on smooth surfaces, possibly indicating inverted micelles. These results suggest a structural role for rhodopsin in maintaining the photoreceptor membrane lipids in a bilayer configuration.
D000818:Animals; D002462:Cell Membrane / Q000648:ultrastructure*; D005614:Freeze Fracturing; D008051:Lipid Bilayers; D008081:Liposomes; D009682:Magnetic Resonance Spectroscopy; D008854:Microscopy, Electron; D010786:Photoreceptor Cells / Q000648:ultrastructure*; D012168:Retinal Pigments / Q000502:physiology; D012172:Retinaldehyde; D012243:Rhodopsin / Q000502:physiology
D008051:Lipid Bilayers; D008081:Liposomes; D012168:Retinal Pigments; D012243:Rhodopsin; D012172:Retinaldehyde