Acetylcholine retinal

The bottom of the binding pocket is in a position equivalent to the binding site of small cationic neurotransmitters (dopamine, adrenaline, serotonin, acetylcholine,etc.) and to the ionone ring of retinal in opsins. 

Orientational constraints have been collected for a wide variety of molecular systems from synthetic polymers [32, 33] to structural proteins, such as silk [34, 35]. Orientational constraints have also been collected for retinal bound to bacteriorhodopsin [36], suggesting a host of ligand receptor systems that might be studied. Orientational constraints have been collected on other synthetic and biosynthetic polypeptides in bilayer environments, such as Magainin-2, a toxin from frog skin [37], the M2 8 from the acetylcholine receptor [38] and M2-TMP from Influenza A virus [39]. Such studies have led to a description of the orientation of a-helices relative to the bilayer. Proteins such as the fd and Pfl bacteriophage coat proteins have also been... 

Exhibit 4.8). Botulinum toxin (Botox) is being injected as an anti-wrinkle treatment (Exhibit 11.11), and a vitamin A derivative (Retin-A gel, Tretinoin) is prescribed for the treatment of facial wrinkles. Drugs such as tacrine and donepezil, which work by attacking enzymes that breakdown acetylcholine, have been approved for boosting memory. Sildenafil (Viagra, Pfizer) is used to treat sexual dysfunction (Exhibit 3.15). 

Wehrwein, E. Xhompson, S. A. Coulibaly, S. F. Linn, D. M. Linn, C. L. Acetylcholine protection of adult pig retinal ganglion cells from glutamate-induced excitotoxicity. Investigative Ophthalmol. Visual Sci. 2004, 45, 1531-1543. 

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