Site of attachment of 11-cis-retinal in bovine rhodopsin.
A dipeptide containing the binding site for retinal in bovine rhodopsin has been isolated and its sequence determined. Rhodopsin containing [11-3H]retinal was prepared in chromatographically pure form, and the [3H]retinal was reductively linked to its binding site on opsin by using borane--dimethylamine. The [3H]retinylopsin in octyl glucoside was exhaustively digested with Pronase, and its peptides were separated on silica gel in chloroform/methanol/ammonia [Bownds, D. (1967) Nature (London) 216, 1178--1181] followed by silica gel thin-layer chromatography in two solvent systems. The major retinyl peptide was shown to be alanyl-N epsilon-retinyllysine by amino acid composition, 3H content, and amino acid sequence analysis. The retinyl binding site is located in the carboxyl-terminal region of rhodopsin: when rod cell disk membranes containing [3H]retinal rhodopsin were digested with thermolysin and then reacted with sodium borohydride or borane--dimethylamine, [3H]retinal was reduced onto the F2 (Mr congruent to 6000) fragment, which derives from rhodopsin's carboxyl-terminal region.
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D004591:Electrophoresis, Polyacrylamide Gel; D005136:Eye Proteins / Q000302:isolation & purification / Q000378:metabolism; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010446:Peptide Fragments; D010786:Photoreceptor Cells / Q000032:analysis*; D011402:Pronase; D012168:Retinal Pigments / Q000378:metabolism*; D012243:Rhodopsin / Q000378:metabolism*; D012374:Rod Cell Outer Segment / Q000032:analysis*; D017299:Rod Opsins; D013820:Thermolysin; D014801:Vitamin A / Q000378:metabolism*
D005136:Eye Proteins; D010446:Peptide Fragments; D012168:Retinal Pigments; D017299:Rod Opsins; C028370:alanyl-N(epsilon)-retinyllysine; D014801:Vitamin A; D012243:Rhodopsin; D011402:Pronase; D013820:Thermolysin