Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India.
Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India.
Arch Biochem Biophys. 2023 Dec;750:109820. doi: 10.1016/j.abb.2023.109820. Epub 2023 Nov 11.
The nucleocapsid (N) protein of SARS-CoV-2 plays a pivotal role in encapsulating the viral genome. Developing antiviral treatments for SARS-CoV-2 is imperative due to the diminishing immunity of the available vaccines. This study targets the RNA-binding site located in the N-terminal domain (NTD) of the N-protein to identify the potential antiviral molecules against SARS-CoV-2. A structure-based repurposing approach identified the twelve high-affinity molecules from FDA-approved drugs, natural products, and the LOPAC compound libraries that precisely bind to the RNA binding site within the NTD. The interaction of these potential antiviral agents with the purified NTD protein was thermodynamically characterized using isothermal titration calorimetry (ITC). A fluorescence-based plate assay to assess the RNA binding inhibitory activity of small molecules against the NTD has been employed, and the selected compounds exhibited significant RNA binding inhibition with calculated IC values ranging from 8.8 μM to 15.7 μM. Furthermore, the antiviral efficacy of these compounds was evaluated using in vitro cell-based assays targeting the replication of SARS-CoV-2. Remarkably, two compounds, Telmisartan and BMS-189453, displayed potential antiviral activity against SARS-CoV-2, with EC values of approximately 1.02 μM and 0.98 μM, and a notable selective index of >98 and > 102, respectively. This study gives valuable insight into developing therapeutic interventions against SARS-CoV-2 by targeting the N-protein, a significant effort given the global public health concern posed due to the virus re-emergence and long COVID-19 disease.
新型冠状病毒的核衣壳(N)蛋白在包裹病毒基因组方面起着关键作用。由于现有疫苗的免疫效力逐渐减弱,开发针对新型冠状病毒的抗病毒治疗方法势在必行。本研究针对 N 蛋白 N 端结构域(NTD)中的 RNA 结合位点,旨在寻找针对新型冠状病毒的潜在抗病毒分子。基于结构的再利用方法从 FDA 批准的药物、天然产物和 LOPAC 化合物库中鉴定出 12 种与 NTD 内的 RNA 结合位点具有高亲和力的分子。使用等温滴定量热法(ITC)对这些潜在抗病毒药物与纯化的 NTD 蛋白的相互作用进行了热力学表征。采用基于荧光的平板测定法评估小分子对 NTD 的 RNA 结合抑制活性,选择的化合物对 NTD 的 RNA 结合具有显著的抑制作用,计算得到的 IC 值范围为 8.8 μM 至 15.7 μM。此外,还通过针对新型冠状病毒复制的体外细胞测定法评估了这些化合物的抗病毒功效。值得注意的是,两种化合物(替米沙坦和 BMS-189453)对新型冠状病毒具有潜在的抗病毒活性,EC 值分别约为 1.02 μM 和 0.98 μM,选择性指数分别大于 98 和 102。本研究为针对 N 蛋白开发针对新型冠状病毒的治疗干预措施提供了有价值的见解,鉴于该病毒再次出现和长期 COVID-19 疾病对全球公共卫生构成的威胁,这是一项重要的努力。