AChE substrate
Solution of the three-dimensional (3D) structure of Torpedo californica acetylcholinesterase (TcAChE) in 1991 [1] opened up new horizons in research on an enzyme that had already been the subject of intensive investigation. The unanticipated structure of this extremely rapid enzyme, in which the active site was found to be buried at the bottom of a deep and narrow gorge, lined by 14 aromatic residues (colored dark magenta), led to a revision of the views then held concerning substrate traffic, recognition and hydrolysis [2]. This led to a series of theoretical and experimental studies, which took advantage of recent advances in theoretical techniques for treatment of proteins, such as
molecular dynamics and electrostatics and to site-directed mutagenesis, utilizing suitable expression
systems. Acetylcholinesterase hydrolysizes the neurotransmitter acetylcholine (ACh), producing choline and an acetate group. ACh directly binds Ser200 (via its nucleophilic Oγ atom) within the catalytic triad (Ser200, His440, and Glu327) (ACh/TcAChE structure 2ace). The residues Trp84 and Phe330 are also important in the ligand recognition [3]. After this binding acetylcholinesterase hydrolysizes ACh.
- ↑ Sussman JL, Harel M, Frolow F, Oefner C, Goldman A, Toker L, Silman I. Atomic structure of acetylcholinesterase from Torpedo californica: a prototypic acetylcholine-binding protein. Science. 1991 Aug 23;253(5022):872-9. PMID:1678899
- ↑ Botti SA, Felder CE, Lifson S, Sussman JL, Silman I. A modular treatment of molecular traffic through the active site of cholinesterase. Biophys J. 1999 Nov;77(5):2430-50. PMID:10545346
- ↑ Raves ML, Harel M, Pang YP, Silman I, Kozikowski AP, Sussman JL. Structure of acetylcholinesterase complexed with the nootropic alkaloid, (-)-huperzine A. Nat Struct Biol. 1997 Jan;4(1):57-63. PMID:8989325