title: Reason for the lack of light-dark adaptation in pharaonis phoborhodopsin: reconstitution with 13-cis-retinal.
abstract: The reconstitution of pharaonis phoborhodopsin was performed by incubation of its opsin with 13-cis-retinal. Spectrum change was very slow, and two phases of the change were observed: the first and second phases are due to the transient formation of 13-cis pigment and spontaneous isomerization to all-trans-retinal, respectively. Slow binding supports an idea that the retinal binding pocket of ppR is highly restricted. Being bent in the configuration, 13-cis-retinal cannot be accommodated in the pocket due to the steric hindrance. This is a possible reason for the lack of light-dark adaptation.
authors.affiliation: Department of Biophysical Chemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Hirayma
authors.forename: N
authors.initials: N
authors.lastname: Kamo
authors.forename: Y
authors.initials: Y
authors.lastname: Imamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Shichida
authors.forename: T
authors.initials: T
authors.lastname: Yoshizawa
mesh_terms: D019843:Archaeal Proteins; D001436:Bacteriorhodopsins / Q000737:chemistry / Q000528:radiation effects*; D002338:Carotenoids; D003624:Darkness; D004224:Diterpenes; D016931:Halobacteriales / Q000737:chemistry / Q000528:radiation effects; D025602:Halorhodopsins; D008027:Light; D010777:Photochemistry; D012172:Retinaldehyde / Q000737:chemistry; D025603:Sensory Rhodopsins; D013053:Spectrophotometry
chemical_list: D019843:Archaeal Proteins; D004224:Diterpenes; D025602:Halorhodopsins; D025603:Sensory Rhodopsins; C061508:sensory rhodopsin II protein, archaeal; D002338:Carotenoids; C031338:13-cis-retinal; D001436:Bacteriorhodopsins; D012172:Retinaldehyde