title: Molecular properties of rod and cone visual pigments from purified chicken cone pigments to mouse rhodopsin in situ.
abstract: We have investigated the molecular properties of rod and cone visual pigments to elucidate the differences in the molecular mechanism(s) of the photoresponses between rod and cone photoreceptor cells. We have found that the cone pigments exhibit a faster pigment regeneration and faster decay of meta-II and meta-III intermediates than the rod pigment, rhodopsin. Mutagenesis experiments have revealed that the amino acid residues at positions 122 and 189 in the opsins are the determinants for these differences. In order to study the relationship between the molecular properties of visual pigments and the physiology of rod photoreceptors, we used mouse rhodopsin as a model pigment because, by gene-targeting, the spectral properties of the pigment can be directly correlated to the physiology of the cells. In the present paper, we summarize the spectroscopic properties of cone pigments and describe our studies with mouse rhodopsin utilizing a high performance charge coupled device (CCD) spectrophotometer.
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan. imai@vision-kyoto-u.jp
authors.forename: Hiroo
authors.initials: H
authors.lastname: Imai
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kuwayama
authors.forename: Akishi
authors.initials: A
authors.lastname: Onishi
authors.forename: Takefumi
authors.initials: T
authors.lastname: Morizumi
authors.forename: Osamu
authors.initials: O
authors.lastname: Chisaka
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Shichida
mesh_terms: D000818:Animals; D002645:Chickens; D051379:Mice; D008958:Models, Molecular; D017949:Retinal Cone Photoreceptor Cells / Q000737:chemistry; D012168:Retinal Pigments / Q000737:chemistry*; D017948:Retinal Rod Photoreceptor Cells / Q000737:chemistry; D012243:Rhodopsin / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D012168:Retinal Pigments; D012243:Rhodopsin