title: Asp83, Glu113 and Glu134 are not specifically involved in Schiff base protonation or wavelength regulation in bovine rhodopsin.
abstract: Site-specific mutagenesis was employed to investigate the proposed contribution of proton-donating residues (Glu, Asp) in the membrane domains of bovine rhodopsin to protonation of the Schiff base-linking protein and chromophore or to wavelength modulation of this visual pigment. Three point-mutations were introduced to replace the highly conserved residues Asp83 by Asn (D83N), Glu113 by Gln (E113 Q) or Glu134 by Asp (E134D), respectively. All 3 substitutions had only marginal effects on the spectral properties of the final pigment (less than or equal to 3 nm blue-shift relative to native rhodopsin). Hence, none of these residues by itself is specifically involved in Schiff base protonation or wavelength modulation of bovine rhodopsin.
authors.affiliation: Department of Biochemistry, University of Nijmegen, The Netherlands.
authors.forename: J J
authors.initials: JJ
authors.lastname: Janssen
authors.forename: G L
authors.initials: GL
authors.lastname: De Caluwé
authors.forename: W J
authors.initials: WJ
authors.lastname: De Grip
mesh_terms: D000818:Animals; D001224:Aspartic Acid; D002417:Cattle; D004735:Energy Transfer; D019204:GTP-Binding Proteins / Q000502:physiology; D005971:Glutamates; D009154:Mutation; D015202:Protein Engineering; D011994:Recombinant Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000502:physiology; D012168:Retinal Pigments / Q000096:biosynthesis*; D012243:Rhodopsin / Q000031:analogs & derivatives / Q000096:biosynthesis* / Q000235:genetics; D012545:Schiff Bases; D015290:Second Messenger Systems / Q000528:radiation effects; D013053:Spectrophotometry
chemical_list: D005971:Glutamates; D011994:Recombinant Proteins; D012168:Retinal Pigments; D012545:Schiff Bases; D001224:Aspartic Acid; D012243:Rhodopsin; D019204:GTP-Binding Proteins