title: On the bioactive conformation of the rhodopsin chromophore: absolute sense of twist around the 6-s-cis bond.
abstract: Incubation of opsin with synthetic 6-s-locked retinoids 2a and 2b only led to pigment formation from the alpha-locked 2a, the CD spectrum of which was similar to that of native rhodopsin (Rh). This establishes that the 6-s-bond of the chromophore in rhodopsin is cis, and that its helicity is negative. Earlier cross-linking studies showed that the 11-cis to all-trans photoisomerization occurring in the batho-Rh to lumi-Rh conversion induces a flip over of the side carrying the ring moiety. The GTP-binding assay of pigment Rh-(2a), incorporating retinal analogue 2a, has shown that its activity is 80% that of the native pigment. That is, the overall conformation around the 6-s bond is retained in the steps leading to G-protein activation.
authors.affiliation: Department of Chemistry, Columbia University, New York, NY 10027, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Fujimoto
authors.forename: J
authors.initials: J
authors.lastname: Ishihara
authors.forename: S
authors.initials: S
authors.lastname: Maki
authors.forename: N
authors.initials: N
authors.lastname: Fujioka
authors.forename: T
authors.initials: T
authors.lastname: Wang
authors.forename: T
authors.initials: T
authors.lastname: Furuta
authors.forename: N
authors.initials: N
authors.lastname: Fishkin
authors.forename: B
authors.initials: B
authors.lastname: Borhan
authors.forename: N
authors.initials: N
authors.lastname: Berova
authors.forename: K
authors.initials: K
authors.lastname: Nakanishi
mesh_terms: D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D008958:Models, Molecular; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012172:Retinaldehyde / Q000031:analogs & derivatives; D012243:Rhodopsin / Q000737:chemistry*; D017299:Rod Opsins / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
chemical_list: D017299:Rod Opsins; D012243:Rhodopsin; D012172:Retinaldehyde