Sandbox Reserved 895: Difference between revisions

[[Image:RPE65_Emixustat_and_Palmitate_PyMOL.jpg|thumb|center|512 px|alt=Figure 1B: Emixustat and palmitate ester in Binding Pocket| '''Figure 1B:''' Bovine RPE65 Binding Pocket with Emixustat and palmitate ester generated in PyMOL using PDB: ''4RSV'']]

In order to stimulate the phototransduction pathway, 11-''cis''-retinal must be absorbed into the body. 11-''cis''-retinal often referred as Vitamin A, is an important dietary vitamin that starts the cascade of phototransduction. Once absorbed into the body and brought to the photoreceptor outer segment (POS), 11-''cis''-retinal is conjugated to opsin to form the rhodopsin complex. Upon light incidence, 11-''cis''-retinal is converted though a photo-isomerization reaction into all-''trans''-retinal. The conversion of 11-''cis''-retinal to all-''trans''-retinal causes a conformation change in the rhodopsin complex. This conformation change activates a G-protein coupled protein transducing which triggers the subsequent phototransduction cascade. The generated all-''trans''-retinal then dissociates from the rhodopsin complex which frees the opsin protein to bind another 11-''ci''s-retinal molecule and restart the phototransduction cascade. All-''trans''-retinal must be converted back into 11-''cis''-retinal to serve as the chromophore for the phototransduction cascade. To regenerate 11-''cis''-retinal a series of enzyme catalyzed chemical reactions must take place. These reactions take place within the photoreceptor outer segment (hPOS) as well as the retinal pigment epithelium (hRPE).