Department of Biochemistry, University of Zürich, Zürich, Switzerland.
PLoS Negl Trop Dis. 2009;3(1):e356. doi: 10.1371/journal.pntd.0000356. Epub 2009 Jan 13.
The non-structural 3 protease (NS3pro) is an essential flaviviral enzyme and therefore one of the most promising targets for drug development against West Nile virus (WNV) and dengue infections.
In this work, a small-molecule inhibitor of the WNV NS3pro has been identified by automatic fragment-based docking of about 12000 compounds and testing by nuclear magnetic resonance (NMR) spectroscopy of only 22 molecules. Specific binding of the inhibitor into the active site of NS3pro and its binding mode are confirmed by 15N-HSQC NMR spectra. The inhibitory activity is further validated by an enzymatic assay and a tryptophan fluorescence quenching assay.
The inhibitor [4-(carbamimidoylsulfanylmethyl)-2,5-dimethylphenyl]-methylsulfanylmethanimidamide has a good ratio of binding affinity versus molecular weight (ligand efficiency of 0.33 kcal/mol per non-hydrogen atom), and thus has good potential as lead compound for further development to combat West Nile virus infections.
非结构蛋白 3 蛋白酶（NS3pro）是一种重要的黄病毒酶，因此是针对西尼罗河病毒（WNV）和登革热感染开发药物的最有前途的靶点之一。
在这项工作中，通过对大约 12000 种化合物进行自动基于片段的对接，并仅对 22 种化合物进行核磁共振（NMR）光谱测试，鉴定出一种WNV NS3pro 的小分子抑制剂。通过 15N-HSQC NMR 光谱证实了抑制剂在 NS3pro 活性部位的特异性结合及其结合模式。通过酶测定和色氨酸荧光猝灭测定进一步验证了抑制活性。
抑制剂[4-（氨甲酰基硫代磺酰甲基）-2,5-二甲基苯基]-甲硫基亚甲脒具有良好的结合亲和力与分子量比（每个非氢原子的配体效率为 0.33 千卡/摩尔），因此具有作为进一步开发以对抗西尼罗河病毒感染的先导化合物的良好潜力。
