Substrates

'''AChE substrate'''

Solution of the three-dimensional (3D) structure of [http://en.wikipedia.org/wiki/Pacific_electric_ray ''Torpedo californica''] [[acetylcholinesterase]] (''Tc''AChE) in 1991 <ref name="Sussman">PMID:1678899</ref> opened up new horizons in research on an [http://en.wikipedia.org/wiki/Enzyme enzyme] that had already been the subject of intensive investigation. The unanticipated structure of this extremely rapid enzyme, in which the [http://en.wikipedia.org/wiki/Active_site active site] was found to be buried at the bottom of a <scene name='2ace/Active_site/3'>deep and narrow gorge</scene>, lined by <scene name='2ace/Active_site/4'>14 aromatic residues</scene> <font color='darkmagenta'><b>(colored dark magenta)</b></font>, led to a revision of the views then held concerning [http://en.wikipedia.org/wiki/Substrate_(biochemistry) substrate] traffic, recognition and hydrolysis <ref name="Botti">PMID:10545346</ref>. This led to a series of theoretical and experimental studies, which took advantage of recent advances in theoretical techniques for treatment of [http://en.wikipedia.org/wiki/Protein proteins], such as

[http://en.wikipedia.org/wiki/Molecular_dynamics molecular dynamics] and [http://en.wikipedia.org/wiki/Electrostatics electrostatics] and to [http://en.wikipedia.org/wiki/Site-directed_mutagenesis site-directed mutagenesis], utilizing suitable expression

systems. [http://en.wikipedia.org/wiki/Acetylcholinesterase Acetylcholinesterase] [http://en.wikipedia.org/wiki/Hydrolysis hydrolysizes] the [http://en.wikipedia.org/wiki/Neurotransmitter neurotransmitter] [http://en.wikipedia.org/wiki/Acetylcholine acetylcholine] <scene name='2ace/Cv/2'>(ACh)</scene>, producing <scene name='2ace/Cv/3'>choline and an acetate</scene> group. ACh directly binds <scene name='22/22/Cv/1'>Ser200</scene> (via its [http://en.wikipedia.org/wiki/Nucleophile nucleophilic] Oγ atom) within the <scene name='2ace/Cv/5'>catalytic triad (Ser200, His440, and Glu327)</scene> (ACh/''Tc''AChE structure [[2ace]]). The residues <scene name='2ace/Cv/6'>Trp84 and Phe330</scene> are also important in the [http://en.wikipedia.org/wiki/Ligand ligand] recognition <ref name="Raves">PMID:8989325</ref>. After this binding acetylcholinesterase <scene name='2ace/Cv/7'>hydrolysizes</scene> ACh.