[Synthesis of visual rhodopsin in a cell-free translation system. II. Functional properties of recombinant rhodopsin...

Functional expression of bovine visual rhodopsin in the cell-free translation system with cotranslational insertion of the protein into phosphatidylcholine liposomes is described. The recombinant rhodopsin has spectral and functional properties similar to those of natural rhodopsin from bovine retina. Two mutant rhodopsins with amino acid substitutions in the hydrophilic C-terminal domain were obtained using oligonucleotide-directed mutagenesis. It was found that substitution Cys-316----Ser does not affect rhodopsin's ability to activate the visual amplification cascade, whereas double mutation Asp-330----Asn, Asp-331----Asn dramatically lowers the rhodopsin functional activity.