Indication of the metarhodopsin I-II transition by absorption-changes of Eriochromblack T.
The dye eriochromblack T (erio T), added to an aqueous suspension of bovine retinal outer segments solubilized by digitonin, shows a light-induced absorption-increase at lambda = 645 nm. Erio T is shown to directly interact with miscellar metarhodopsin I and metarhodopsin II. The absorption-changes of erio T can be regarded as an indication of the transition from the metarhodopsin I conformation (with associated Ca2+) to the metarhodopsin II conformation (with associated H+).
D000818:Animals; D001391:Azo Compounds; D002417:Cattle; D004396:Coloring Agents; D004072:Digitonin; D006863:Hydrogen-Ion Concentration; D008027:Light; D009282:Naphthalenesulfonates; D010777:Photochemistry; D010786:Photoreceptor Cells / Q000502:physiology*; D011487:Protein Conformation; D012168:Retinal Pigments / Q000031:analogs & derivatives; D012243:Rhodopsin / Q000031:analogs & derivatives; D013053:Spectrophotometry
D001391:Azo Compounds; D004396:Coloring Agents; D009282:Naphthalenesulfonates; D012168:Retinal Pigments; C013110:metarhodopsins; D012243:Rhodopsin; D004072:Digitonin