title: Bathoiodopsin, a primary intermediate of iodopsin at physiological temperature.
abstract: Measurement of the primary photochemical reaction of iodopsin, a chicken red-sensitive cone visual pigment, was carried out at room temperature by using picosecond (ps) laser photolysis. Excitation of iodopsin with a ps green pulse (pulse width, 21 ps) caused the instantaneous formation of a bathochromic product, which was stable on a ps time scale. This product may correspond to "bathoiodopsin," which was detected by low-temperature spectrophotometry. Although bathoiodopsin produced at the temperature of liquid nitrogen or helium reverted to the original pigment (iodopsin) on warming (above -170 degrees C), the bathoiodopsin produced at physiological temperature decayed to all-trans-retinal and R-photopsin (the protein moiety of iodopsin) presumably through several intermediates. The absorption maximum of bathoiodopsin at room temperature was at 625 nm, a wave-length slightly shorter than that measured at low temperature (lambda max, 640 nm). The extinction coefficient of bathoiodopsin at room temperature was lower than that at low temperature and close to that of the original iodopsin at room temperature.
authors: Department of Biophysics, Faculty of Science, Kyoto University, Japan.
authors: H
authors: H
authors: Kandori
authors: T
authors: T
authors: Mizukami
authors: T
authors: T
authors: Okada
authors: Y
authors: Y
authors: Imamoto
authors: Y
authors: Y
authors: Fukada
authors: Y
authors: Y
authors: Shichida
authors: T
authors: T
authors: Yoshizawa
mesh_terms: D000818:Animals; D002645:Chickens; D003118:Color Perception; D066298:In Vitro Techniques; D010777:Photochemistry; D012168:Retinal Pigments / Q000737:chemistry; D017299:Rod Opsins; D013057:Spectrum Analysis
chemical_list: D012168:Retinal Pigments; D017299:Rod Opsins; C034941:iodopsin