[243] Methodology of vitamin A and visual pigments

摘要: Publisher Summary This chapter discusses methodology for the assay and preparation of vitamin A visual pigments, such as rhodopsin, rod opsin, iodopsin, cone opsin. The rhodopsin depends upon fact that bleaches in light to all-trans retinal Opsin has no absorption at wavelengths longer than about 300 nm, but some visible, this varies with pH purity preparation. is therefore best performed presence hydroxylamine combines form retinaldehyde oxime, a compound essentially 450 nm. opsin its molar equivalent 11-cis-retinal characteristic properties. Iodopsin, pigment, been prepared from chicken, pigeon, sea turtle retinas. As detergent digitonin required solubilize it. Because all these animals have both rods cones their retinas, extracts contain mixtures must detect iodopsin what usually an excess rhodopsin.