title: Resonance Raman study of the dark-adapted form of the purple membrane protein.
abstract: The resonance Raman spectrum of the dark-adapted form of the purple membrane protein (bacteriorhodopsin) has been obtained and is compared to the light-adapted pigment and model chromophore spectra. As in the light-adapted form, the chromophore-protein linkage is found to be a protonated Schiff base. Electron delocalization appears to play the dominant role in color regulation. The dark-adapted spectrum indicates a conformation closer to 13-cis than the light-adapted spectrum.
mesh_terms: D001436:Bacteriorhodopsins; D002338:Carotenoids; D003624:Darkness; D006217:Halobacterium; D011487:Protein Conformation; D012172:Retinaldehyde; D013059:Spectrum Analysis, Raman
chemical_list: D002338:Carotenoids; D001436:Bacteriorhodopsins; D012172:Retinaldehyde