Asp83, Glu113 and Glu134 are not specifically involved in Schiff base protonation or wavelength regulation in bovine rhodopsin

[摘要]

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 (E₁₁₃Q) or Glu₁₃₄ by Asp (E₁₃₄D), respectively. All 3 substitutions had only marginal effects on the spectral properties of the final pigment (⩽ 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.

[学科分类] 生物化学/生物物理

[关键词] Amino acid substitution;Baculovirus;Heterologous expression;Rhodopsin;Spectral property;Site selective mutagenesis;AcNPV;Autographa californica nuclear polyhedrosis virus;bp;base pair;dpi;days post-infection;MOI;multiplicity of infection;CHAPS;3-[(3-cholamidopropyl)dimethylammonio]propanosulfonate;DTE;1;4-dithioerythritol;EDTA;(ethylene-1;2-diamine)N-tetraacetic acid;Con A;concanavalin A;G-protein;GTP-binding protein or transducin;RT;room temperature;v-ops;opsin produced in vitro by recombinant baculovirus;v-rho;rhodopsin obtained by incubation of v-ops with 11-Z-retinal