Laboratory of Toxicant Analysis, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, 27 Taiping Road, Haidian District, 100850, Beijing, China.
Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Haidian District, 100850, Beijing, China.
Chem Biol Interact. 2024 Jun 1;396:111061. doi: 10.1016/j.cbi.2024.111061. Epub 2024 May 17.
Nerve agents pose significant threats to civilian and military populations. The reactivation of acetylcholinesterase (AChE) is critical in treating acute poisoning, but there is still lacking broad-spectrum reactivators, which presents a big challenge. Therefore, insights gained from the reactivation kinetic analysis and molecular docking are essential for understanding the behavior of reactivators towards intoxicated AChE. In this research, we present a systematic determination of the reactivation kinetics of three V agents-inhibited four human ChEs [(AChE and butyrylcholinesterase (BChE)) from either native or recombinant resources, namely, red blood cell (RBC) AChE, rhAChE, hBChE, rhBChE) reactivated by five standard oximes. We unveiled the effect of native and recombinant ChEs on the reactivation kinetics of V agents ex vitro, where the reactivation kinetics characteristic of Vs-inhibited BChE was reported for the first time. In terms of the inhibition type, all of the five oxime reactivators exhibited noncompetitive inhibition. The inhibition potency of these reactivators would not lead to the difference in the reactivation kinetics between native and recombinant ChE. Despite the significant differences between the native and recombinant ChEs observed in the inhibition, aging, and spontaneous reactivation kinetics, the reactivation kinetics of V agent-inhibited ChEs by oximes were less differentiated, which were supported by the ligand docking results. We also found differences in the reactivation efficiency between five reactivators and the phosphorylated enzyme, and molecular dynamic simulations can further explain from the perspectives of conformational stability, hydrogen bonding, binding free energies, and amino acid contributions. By Poisson-Boltzmann surface area (MM-PBSA) calculations, the total binding free energy trends aligned well with the experimental k values.
神经毒剂对平民和军事人员构成重大威胁。乙酰胆碱酯酶（AChE）的重激活在治疗急性中毒中至关重要，但仍缺乏广谱重激活剂，这是一个巨大的挑战。因此，从重激活动力学分析和分子对接中获得的见解对于理解重激活剂对中毒 AChE 的作用至关重要。在这项研究中，我们系统地确定了三种 V 型剂抑制的四种人 ChE 的重激活动力学[（来自天然或重组资源的红细胞（RBC）AChE、rhAChE、hBChE、rhBChE），用五种标准肟重新激活）。我们揭示了天然和重组 ChE 对 V 型剂在体外重激活动力学的影响，首次报道了 V 型剂抑制的 BChE 的重激活动力学特征。就抑制类型而言，所有五种肟重激活剂均表现为非竞争性抑制。这些重激活剂的抑制效力不会导致天然和重组 ChE 之间重激活动力学的差异。尽管在抑制、老化和自发重激活动力学中观察到天然和重组 ChE 之间存在显著差异，但肟对 V 型剂抑制的 ChE 的重激活动力学差异较小，这得到了配体对接结果的支持。我们还发现五种重激活剂与磷酸化酶之间的重激活效率存在差异，分子动力学模拟可以从构象稳定性、氢键、结合自由能和氨基酸贡献等方面进一步解释。通过泊松-玻尔兹曼表面面积（MM-PBSA）计算，总结合自由能趋势与实验 k 值吻合良好。
