The 3, 4-didehydroretinal chromophore of goldfish porphyropsin

✍ Scribed by Tsin, Andrew T. C. ;Santos, Frank R.

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 474 KB
• Volume: 235
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402350204

✦ Synopsis

The isomeric configuration of the 3,4-didehydroretinal chromophore of goldfish porphyropsin was determined by high performance liquid chromatography (HPLC) and by the regeneration of this visual pigment with authentic isomers of 3,Cdidehydroretinal. A nonisomerizing, quantitative method using hydroxylamine and methylene chloride was employed to extract the 3,4-didehyroretinal chromophore from the rod outer segment membrane (containing the porphyropsin). When this extracted chromophore was injected into the HPLC, only a single major peak was observed and this peak coeluted with the authentic 11-cis 3'4-didehydroretinyl oxime. This suggests that the chromophore of goldfish porphyropsin is 11-cis 3,4-didehydroretinal. When the bleached rod outer segments (containing the opsin) were incubated with different 3,4-didehydroretinal isomers (13-cis7 11-cis, g-cis, and all-trans), only the 11- cis isomer resulted in the degeneration of porphyropsin. This also suggests that the porphyropsin chromophore exists in the 11-cis configuration.