title: Photolysis of rhodopsin results in deprotonation of its retinal Schiff's base prior to formation of metarhodopsin II.
abstract: Absorption changes following photolysis of bovine rhodopsin in mildly sonicated membrane suspensions are monitored at 25 degrees C. Difference spectra collected at 17 times between 1 microsecond and 75 ms following excitation are analyzed globally using singular value decomposition and non-linear least-squares fitting techniques. The results are not consistent with the simple scheme: Lumirhodopsin-->Metarhodopsin I<-->Metarhodopsin II, but indicate that an intermediate with a deprotonated Schiff's base is formed nearly simultaneously with metarhodopsin I upon the decay of Lumirhodopsin.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Santa Cruz 95064.
authors.forename: T E
authors.initials: TE
authors.lastname: Thorgeirsson
authors.forename: J W
authors.initials: JW
authors.lastname: Lewis
authors.forename: S E
authors.initials: SE
authors.lastname: Wallace-Williams
authors.forename: D S
authors.initials: DS
authors.lastname: Kliger
mesh_terms: D000818:Animals; D002417:Cattle; D066298:In Vitro Techniques; D010782:Photolysis; D011522:Protons; D012172:Retinaldehyde / Q000737:chemistry; D012243:Rhodopsin / Q000031:analogs & derivatives / Q000737:chemistry / Q000528:radiation effects*; D012545:Schiff Bases / Q000737:chemistry
chemical_list: D011522:Protons; D012545:Schiff Bases; C013110:metarhodopsins; D012243:Rhodopsin; D012172:Retinaldehyde