title: Photoactivated conformational changes in rhodopsin: a time-resolved spin label study.
abstract: Rhodopsin has been selectively spin-labeled near the cytoplasmic termini of helices C and G. Photoactivation with a light flash induces an electron paramagnetic resonance spectral change in the millisecond time domain, coincident with the appearance of the active metarhodopsin II intermediate. The spectral change is consistent with a small movement near the cytoplasmic termination of the C helix and reverses upon formation of the MIII state. These results provide an important link between the optical changes associated with the retinal chromophore and protein conformational states.
authors.affiliation: Jules Stein Eye Institute, Los Angeles, CA.
authors.forename: Z T
authors.initials: ZT
authors.lastname: Farahbakhsh
authors.forename: K
authors.initials: K
authors.lastname: Hideg
authors.forename: W L
authors.initials: WL
authors.lastname: Hubbell
mesh_terms: D000595:Amino Acid Sequence; D004578:Electron Spin Resonance Spectroscopy; D008027:Light; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012243:Rhodopsin / Q000737:chemistry*; D013113:Spin Labels; D013696:Temperature
chemical_list: D013113:Spin Labels; D012243:Rhodopsin