A model of the light dependent regulation of retinal rod phosphodiesterase, guanylate cyclase and the cation flux.

摘要: In the 1880’s Kuhn dissected dark adapted eyes and observed that retina’s red/purple “visual pigment”, changed rapidly to a pale yellow upon illumination. Years later, George Wald Ruth Hubbard chemically characterized rod visual pigment as consisting of opsin 11-cis retinal (Wald, 1968). They demonstrated photoisomerization rhodopsin was driven by photon induced change in configuration (to all-trans), which accompanied conformational changes protein opsin. Subsequently, Wald, Yoshizawa others were able identify series spectral intermediates appeared rapid succession following illumination rhodopsin. The early could only be captured stabilization at low temperatures or ultrafast spectroscopy. major photoconformers are called batho, hypso, meta I, II III (Wald 1968; Birge, 1981). conformation subsequently found enzymatically active (see below).