Acetylcholinesterase

V. Control Mechanisms

AChE is unique because it also has a peripheral binding site which is located at the base of the gorge(6).  The two important amino acid residues in this site Tyr-70 and Trp-279 interact with proteins such as Fasciculin, a snake toxin, to inhibit access to the active site(10).  To see the location of these two residues, Tyr in blue and Trp in green,  push here.    The activity of AChE is not stopped by binding of things such as fasciculin, but it is decreased.

     Another form of control has been examined in which five aromatic residues, Tyr-334, Try-121, Phe-330, Phe-331, and Phe-290 block the entrance of the gorge approximately 12 A from the bottom.   It is thought that these residues must reorient themselves to allow substrate to reach the active site(11).  To view these five residues push here.

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