Lin Yu-Feng, Lai Hsueh-Chou, Lin Chen-Sheng, Hung Ping-Yi, Kan Ju-Ying, Chiu Shih-Wen, Lu Chih-Hao, Petrova Svetlana F, Baltina Lidia, Lin Cheng-Wen
Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung 41354, Taiwan.
Division of Hepato-Gastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung 404327, Taiwan.
Viruses. 2024 Dec 17;16(12):1926. doi: 10.3390/v16121926.
This study investigated a library of known and novel glycyrrhizic acid (GL) conjugates with amino acids and dipeptide esters, as inhibitors of the DENV NS2B-NS3 protease. We utilized docking algorithms to evaluate the interactions of these GL derivatives with key residues (His51, Asp75, Ser135, and Gly153) within 10 Å of the DENV-2 NS2B-NS3 protease binding pocket (PDB ID: 2FOM). It was found that compounds and exhibited unique binding patterns, forming hydrogen bonds with Asp75, Tyr150, and Gly153. Based on the molecular docking data, conjugates with L-glutamic acid dimethyl ester, with β-alanine ethyl ester, and with aminoethantic acid methyl ester were further demonstrated as potent inhibitors of DENV-2 NS3 protease, with IC50 values below 1 μM, using NS3-mediated cleavage assay. Compound was the most potent, with EC50 values of 0.034 μM for infectivity, 0.042 μM for virus yield, and a selective index over 2000, aligning with its strong NS3 protease inhibition. Compound exhibited better NS3 protease inhibition than compound but showed weaker effects on infectivity and virus yield. While all compounds strongly inhibited viral infectivity post-entry, compound also blocked viral entry. This study provided valuable insights into the interactions between active GL derivatives and DENV-2 NS2B-NS3 protease, offering a comprehensive framework for identifying lead compounds for further drug optimization and design as NS2B-NS3 protease inhibitors against DENV.
本研究调查了一系列已知的和新型的甘草酸（GL）与氨基酸及二肽酯的缀合物，作为登革病毒NS2B - NS3蛋白酶的抑制剂。我们利用对接算法评估这些GL衍生物与登革病毒2型NS2B - NS3蛋白酶结合口袋（PDB ID：2FOM）10 Å范围内的关键残基（His51、Asp75、Ser135和Gly153）之间的相互作用。结果发现，化合物 和 呈现出独特的结合模式，与Asp75、Tyr150和Gly153形成氢键。基于分子对接数据，使用NS3介导的切割试验进一步证明，与L - 谷氨酸二甲酯的缀合物 、与β - 丙氨酸乙酯的缀合物 以及与氨基乙磺酸甲酯的缀合物 是登革病毒2型NS3蛋白酶的有效抑制剂，IC50值低于1 μM。化合物 最有效，其感染性的EC50值为0.034 μM，病毒产量的EC50值为0.042 μM，选择性指数超过2000，与其对NS3蛋白酶的强抑制作用一致。化合物 对NS3蛋白酶的抑制作用比化合物 更好，但对感染性和病毒产量的影响较弱。虽然所有化合物在病毒进入后都强烈抑制病毒感染性，但化合物 还能阻断病毒进入。本研究为活性GL衍生物与登革病毒2型NS2B - NS3蛋白酶之间的相互作用提供了有价值的见解，为鉴定先导化合物以进一步进行药物优化和设计作为针对登革病毒的NS2B - NS3蛋白酶抑制剂提供了一个全面的框架。
