狼毒化学成分基于Mpro靶点的虚拟筛选及抗SARS-CoV-2活性分析

In silico Screening of Chemical Components from Langdu(Sellera chamaejasme L.)Based on Mpro Targets and Analysis of Anti SARS-CoV-2 Activity

目的 对瑞香狼毒和狼毒大戟中的化学成分进行基于新型冠状病毒(Severe Acute Respiratory Syndrome-coronavirus-2,SARS-CoV-2)3CL水解酶(Mpro)的抑制剂虚拟筛选以及体外活性验证以为发现抗新型冠状病毒疾病(Corona Virus Disease 2019,COVID-19)治疗药物提供参考。方法 以瑞香狼毒和狼毒大戟中的天然产物为研究对象,以Mpro为靶点,以Mpro晶体结构(PDB ID:6LU7)中的配体小分子N3为阳性对照,采用AutoDock Vina进行分子对接,对结合亲和力和结合构象进行分析并进行基于SARS-CoV-2 Mpro蛋白的体外抑制活性测试。结果 与N3(亲和力为-7.7 kcal/Mol)相比,双黄酮类化合物狼毒素和异狼毒素呈现了最高的Mpro靶点亲和力(-9.7 kcal/Mol),且优于利托那韦、更昔洛韦、利巴韦林、氯喹、达芦那韦、阿巴卡韦等已知抗病毒药物以及其他天然产物的亲和力。对接构象分析发现二者均能有效占据Mpro蛋白结合位点并形成若干重要的氢键结合,其中以异狼毒素为最优,这对于二者与Mpro靶点的结合以及Mpro靶点抑制构象的稳定起着重要作用。异狼毒素在50μM浓度下显示出优于狼毒素的较好的Mpro体外抑制活性。结论 狼毒素和异狼毒素具有基于Mpro靶点抑制SARS-CoV-2病毒的潜在活性,可作为结构优化和抗SARS-CoV-2体内外活性研究的先导化合物。

Objective To explore potential inhibitors of SARS-CoV-2 for the treatment of corona virus disease 2019(COVID-19)from Ruixiang Langdu(Sellera chamaejasme L.)and Langdu Daji(Euphorbia fischeriana Sud.)chemical compo-nents by In silico screening and in vitro Mpro inhibitory activity determination.Methods In silico screening of natural products from Ruixiang Langdu(Sellera chamaejasme L.)and Langdu Daji(Euphorbia fischeriana Sud.)were performed targeting on Mpro(PDB ID:6LU7).The original ligand N3 in 6LU7 was used as the control,the binding affinity and conformation were ana-lyzed.In vitro Mpro inhibitory activity determination was performed.Results Biflavonoids chamaejasmin and isochamaejasmin showed the highest binding affinities(-9.7 kcal/Mol)compared with N3(-7.7 kcal/Mol)and other known antiviral drugs in-cluding ritonavir,ganciclovir,ribavirin,chloroquine,darunavir,abacavir and other natural products.In binding conformation anal-ysis,isochamaejasmin showed more valuable hydrogen bond interactions with the key amino acid residues compared with chamae-jasmin,although both of them occupied the Mpro ligand-binding domain,which was important for the ligand-receptor binding as well as the stability of the binding confrmation.The isochamaejasmin showed better Mpro inhibitory activity than chamaejasmin at the concentration of 50μM.Conclusion Chamaejasmin and isochamaejasmin might be potential inhibitors of SARS-CoV-2 Mpro,and could be served as leads for structure optimization as well as in vitro and in vivo anti-SARS-CoV-2 studies.