Department of Hematology, Rheumatology, and Infectious Diseases, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto Universitygrid.274841.c, Kumamoto, Japan.
Kumamoto Innovative Development Organization, Kumamoto Universitygrid.274841.c, Kumamoto, Japan.
Antimicrob Agents Chemother. 2021 Sep 17;65(10):e0103921. doi: 10.1128/AAC.01039-21. Epub 2021 Jul 6.
The human immunodeficiency virus type 1 (HIV-1) capsid (CA) is an essential viral component of HIV-1 infection and an attractive therapeutic target for antivirals. Here, we report that a small molecule, ACAi-028, inhibits HIV-1 replication by targeting a hydrophobic pocket in the N-terminal domain of CA (CA-NTD). ACAi-028 is 1 of more than 40 candidate anti-HIV-1 compounds identified by screening and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Our binding model showed that ACAi-028 interacts with the Q13, S16, and T19 amino acid residues, via hydrogen bonds, in the targeting pocket of CA-NTD. Using recombinant fusion methods, TZM-bl, time-of-addition, and colorimetric reverse transcriptase (RT) assays, the compound was found to exert anti-HIV-1 activity in the early stage between reverse transcription and proviral DNA integration, without any effect on RT activity , suggesting that this compound may affect HIV-1 core disassembly (uncoating) as well as a CA inhibitor, PF74. Moreover, electrospray ionization mass spectrometry (ESI-MS) also showed that the compound binds directly and noncovalently to the CA monomer. CA multimerization and thermal stability assays showed that ACAi-028 decreased CA multimerization and thermal stability via S16 or T19 residues. These results indicate that ACAi-028 is a new CA inhibitor by binding to the novel hydrophobic pocket in CA-NTD. This study demonstrates that a compound, ACAi-028, targeting the hydrophobic pocket should be a promising anti-HIV-1 inhibitor.
人类免疫缺陷病毒 1 型（HIV-1）衣壳（CA）是 HIV-1 感染的必需病毒成分，也是抗病毒药物的一个有吸引力的治疗靶点。在这里，我们报告说，一种小分子 ACAi-028 通过靶向 CA（CA-NTD）的 N 端结构域中的疏水性口袋来抑制 HIV-1 复制。ACAi-028 是通过筛选和 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）测定法鉴定出的 40 多种候选抗 HIV-1 化合物之一。我们的结合模型表明，ACAi-028 通过氢键与靶向口袋中的 Q13、S16 和 T19 氨基酸残基相互作用。通过重组融合方法、TZM-bl、时间添加和比色逆转录酶（RT）测定，发现该化合物在逆转录和前病毒 DNA 整合之间的早期阶段发挥抗 HIV-1 活性，对 RT 活性没有影响，这表明该化合物可能影响 HIV-1 核心解体（脱壳）以及 CA 抑制剂 PF74。此外，电喷雾电离质谱（ESI-MS）也表明该化合物直接非共价地与 CA 单体结合。CA 多聚化和热稳定性测定表明，ACAi-028 通过 S16 或 T19 残基降低 CA 多聚化和热稳定性。这些结果表明，ACAi-028 通过结合 CA-NTD 中的新型疏水性口袋，是一种新型 CA 抑制剂。本研究表明，针对疏水性口袋的化合物 ACAi-028 可能成为有前途的抗 HIV-1 抑制剂。
