Protein biosynthetic system variety

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... 

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