Based on our proposed “pseudosubstrate envelope” concept, 25 benzothiazole-bearing HIV capsid protein (CA) modulators were designed and synthesized under the guidance of free energy perturbation technology. The most potent compound, IC-1k, exhibited an EC₅₀ of 2.69 nM against HIV-1, being 393 times more potent than the positive control PF74. Notably, IC-1k emerged as the highest ligand efficiency (LE = 0.32) HIV CA modulator, surpassing that of the approved drug lenacapavir (LE = 0.21). Surface plasmon resonance assay and crystallographic analysis confirmed that IC-1k targeted HIV-1 CA within the chemical space of the “pseudosubstrate envelope”. Further mechanistic studies revealed a dual-stage inhibition profile: IC-1k disrupted early-stage capsid–host-factor interactions and promoted late-stage capsid misassembly. Preliminary pharmacokinetic evaluations demonstrated significantly improved metabolic stability in human liver microsomes for IC-1k (T_1/2 = 91.3 min) compared to PF74 (T_1/2 = 0.7 min), alongside a favorable safety profile. Overall, IC-1k presents a promising lead compound for further optimization.

中文翻译：

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具有高配体效率的苯并噻唑 HIV 衣壳调节剂的“伪底物包络”/自由能扰动引导设计和机理研究


基于我们提出的“伪底物包膜”概念，在自由能扰动技术的指导下设计合成了 25 种含苯并噻唑的 HIV 衣壳蛋白 （CA） 调节剂。最有效的化合物 IC-1k 对 HIV-1 的 EC₅₀ 为 2.69 nM，是阳性对照 PF74 的 393 倍。值得注意的是，IC-1k 成为配体效率最高 （LE = 0.32） 的 HIV CA 调节剂，超过了已批准的药物 lenacapavir （LE = 0.21）。表面等离子体共振测定和晶体学分析证实，IC-1k 靶向 “伪底物包膜” 化学空间内的 HIV-1 CA。进一步的机制研究揭示了双阶段抑制特征： IC-1k 破坏了早期衣壳-宿主因子相互作用并促进了晚期衣壳错误组装。初步药代动力学评估表明，与 PF74 （T_1/2 = 0.7 min） 相比，IC-1k （T_1/2 = 91.3 min） 人肝微粒体的代谢稳定性显著改善，同时具有良好的安全性。总体而言，IC-1k 提供了一种有前途的先导化合物，可用于进一步优化。