Functional localization of acetylcholinesterase (AChE) in vertebrate muscle and brain depends on interaction of the tryptophan amphiphilic tetramerization (WAT) sequence, at the C‐terminus of its major splice variant (T), with a proline‐rich attachment domain (PRAD), of the anchoring proteins, collagenous (ColQ) and proline‐rich membrane anchor. The crystal structure of the WAT/PRAD complex reveals a novel supercoil structure in which four parallel WAT chains form a left‐handed superhelix around an antiparallel left‐handed PRAD helix resembling polyproline II. The WAT coiled coils possess a WWW motif making repetitive hydrophobic stacking and hydrogen‐bond interactions with the PRAD. The WAT chains are related by an ∼4‐fold screw axis around the PRAD. Each WAT makes similar but unique interactions, consistent with an asymmetric pattern of disulfide linkages between the AChE tetramer subunits and ColQ. The P59Q mutation in ColQ, which causes congenital endplate AChE deficiency, and is located within the PRAD, disrupts crucial WAT–WAT and WAT–PRAD interactions. A model is proposed for the synaptic AChET tetramer.
Many scientists lack the background to fully utilize the wealth of solved three-dimensional biomacromolecule structures. Thus, a resource is needed to present structure/function information in a user-friendly manner to a broad scientific audience. Proteopediahttp://www.proteopedia.org is an interactive, wiki web-resource whose pages have embedded three-dimensional structures surrounded by descriptive text containing hyperlinks that change the appearance (view, representations, colors, labels) of the adjacent three-dimensional structure to reflect the concept explained in the text.
Functions of biomolecules, in particular enzymes, are usually modulated by structural fluctuations. This is especially the case in a gated diffusion-controlled reaction catalyzed by an enzyme such as acetylcholinesterase. The catalytic triad of acetylcholinesterase is located at the bottom of a long and narrow gorge, but it catalyzes the extremely rapid hydrolysis of the neurotransmitter, acetylcholine, with a reaction rate close to the diffusion-controlled limit. Computational modeling and simulation have produced considerable advances in exploring the dynamical and conformational properties of biomolecules, not only aiding in interpreting the experimental data, but also providing insights into the internal motions of the biomolecule at the atomic level. Given the remarkably high catalytic efficiency and the importance of acetylcholinesterase in drug development, great efforts have been made to understand the dynamics associated with its functions by use of various computational methods. Here, we present a comprehensive overview of recent computational studies on acetylcholinesterase, expanding our views of the enzyme from a microstate of a single structure to conformational ensembles, strengthening our understanding of the integration of structure, dynamics and function associated with the enzyme, and promoting the structure-based and/or mechanism-based design of new inhibitors for it.
1 July 2021 in Progress in Biophysics and Molecular Biology