Bioinformatics Programme, Institute of Biological Sciences, Faculty of Science, Kuala Lumpur 50603, Malaysia.
Department of Anatomy, College of Medicine, University of Babylon, Babylon, Iraq.
Molecules. 2021 Jul 16;26(14):4321. doi: 10.3390/molecules26144321.
Zika virus (ZIKV) represents a re-emerging threat to global health due to its association with congenital birth defects. ZIKV NS2B-NS3 protease is crucial for virus replication by cleaving viral polyprotein at various junctions to release viral proteins and cause cytotoxic effects in ZIKV-infected cells. This study characterized the inhibitory effects of doxycycline against ZIKV NS2B-NS3 protease and viral replication in human skin cells. The in silico data showed that doxycycline binds to the active site of ZIKV protease at a low docking energy (-7.8 Kcal/mol) via four hydrogen bonds with the protease residues TYR1130, SER1135, GLY1151, and ASP83. Doxycycline efficiently inhibited viral NS2B-NS3 protease at average human temperature (37 °C) and human temperature with a high fever during virus infection (40 °C). Interestingly, doxycycline showed a higher inhibitory effect at 40 °C (IC50 = 5.3 µM) compared to 37 °C (9.9 µM). The virus replication was considerably reduced by increasing the concentration of doxycycline. An approximately 50% reduction in virus replication was observed at 20 µM of doxycycline. Treatment with 20 µM of doxycycline reduced the cytopathic effects (CPE), and the 40 µM of doxycycline almost eliminated the CPE of human skin cells. This study showed that doxycycline binds to the ZIKV protease and inhibits its catalytic activity at a low micro-molecular concentration range. Treatment of human skin fibroblast with doxycycline eliminated ZIKV infection and protected the cells against the cytopathic effects of the infection.
寨卡病毒（ZIKV）因其与先天性出生缺陷有关，对全球健康构成了新的威胁。ZIKV NS2B-NS3 蛋白酶对于病毒复制至关重要，它通过在不同的连接处切割病毒多蛋白，释放病毒蛋白，并在 ZIKV 感染的细胞中引起细胞毒性作用。本研究旨在表征强力霉素对 ZIKV NS2B-NS3 蛋白酶和人皮肤细胞中病毒复制的抑制作用。计算数据表明，强力霉素通过与蛋白酶残基 TYR1130、SER1135、GLY1151 和 ASP83 形成四个氢键，以低对接能（-7.8 Kcal/mol）结合到 ZIKV 蛋白酶的活性部位。强力霉素在平均人体温度（37°C）和病毒感染时的人体高温（40°C）下，有效地抑制病毒 NS2B-NS3 蛋白酶。有趣的是，强力霉素在 40°C 时的抑制效果更高（IC50=5.3 µM），而在 37°C 时的抑制效果较低（9.9 µM）。随着强力霉素浓度的增加，病毒复制明显减少。当强力霉素的浓度增加到 20 µM 时，病毒复制减少了约 50%。用 20 µM 的强力霉素处理可减少细胞病变效应（CPE），而 40 µM 的强力霉素几乎消除了人皮肤细胞的 CPE。本研究表明，强力霉素与 ZIKV 蛋白酶结合，并在低微摩尔浓度范围内抑制其催化活性。用强力霉素处理人皮肤成纤维细胞可消除 ZIKV 感染，并保护细胞免受感染的细胞病变效应。
