Accelerating structure-based design of rapid uncharged reactivators of organophosphate-inhibited human acetylcholinesterase by joint X-ray/neutron mechanistic studies

摘要: Nucleophilic oxime reactivators of organophosphate (OP) inhibited human acetylcholinesterase (hAChE) are reactivating antidotes against OP intoxication from nerve agent (e.g., VX, sarin) or pesticide paraoxon) exposure. Within the past decade it has become increasingly clear that for effective and complete recovery antidotal action is needed in both peripheral central nervous system tissues. We using structure-based design to create uncharged bis-oxime possess superior vitro properties reactivation various OP-conjugates hAChE compared known charged pyridinium aldoxime-based therapies. Our strategies involve studying atomic molecular level by employing a combination experimental theoretical techniques, including X-ray neutron crystallography, vibrational spectroscopy simulations. Starting with RS-170B, MMB4 (both charged) RS194B (uncharged) oximes we have obtained view their binding native VX- paraoxon-inhibited hAChE. Neutron spectra 5-50 cm-1 frequency regime indicated softening dynamics paraoxon-bound hAChE, pointing significant picosecond motions acyl pocket loop must accommodate one pesticide’s ethoxy groups. used our crystal structures test bis-oximes, demonstrating several them exceeded efficacy sarin, cyclosarin, VX paraoxon To further reactivator design, working on obtaining which will provide direct observation hydrogen atoms determine protonation states residues bound reactivators. designed conceptually novel, scaffold nucleophilic promising new resource creation adjustable, accelerated centrally active intoxication.