The photoproducts of rhodopsin in the isolated retina of the frog

Abstract

Spectrophotometric measurements on the isolated frog retina show that at the end of a short exposure to light the rhodopsin bleached is found to have been quantitatively converted to a product named “stabilized metarhodopsin II”, which has the same spectrum as metarhodopsin II but does not enter into an equilibrium with metarhodopsin I. If left in the dark, the stabilized meta II is transformed, with a half-return time of 1 min at +15°, into an orange compound. This substance, when compared with the photoproducts described by Matthews et al. (1963), can rather be identified with metarhodopsins I and II in equilibrium than with pararhodopsin ( λ max 465 nm).