Abstract

Flaviviruses are single-stranded RNA viruses predominantly transmitted by the widely distributedAedesmosquitoes in nature. As important human pathogens, the geographic reach of Flaviviruses and their threats to public health are increasing, but there is currently no approved specific drug for treatment. In recent years, the development of peptide antivirals has gained much attention. Natural host defense peptides which uniquely evolved to protect the hosts have been shown to have antiviral properties. In this study, we firstly collected the venom of theAlopecosa nagpagspider from Shangri-La County, Yunnan Province. A defense peptide named Av-LCTX-An1a (Antiviral-Lycotoxin-An1a) was identified from the spider venom, and its anti-dengue serotype-2 virus (DENV2) activity was verified in vitro. Moreover, a real-time fluorescence-based protease inhibition assay showed that An1a functions as a DENV2 NS2B–NS3 protease inhibitor. Furthermore, we also found that An1a restricts zika virus (ZIKV) infection by inhibiting the ZIKV NS2B–NS3 protease. Together, our findings not only demonstrate that An1a might be a candidate for anti-flavivirus drug but also indicate that spider venom is a potential resource library rich in antiviral precursor molecules.Keywords:Alopecosa nagpag;dengue virus;Zika virus;host defense peptide;NS2B–NS3 protease;FlavivirusKey Contribution:This study identifies an antiviral peptide An1a from the venom ofA. nagpagspider. An1a inhibits the infection of DENV2 and ZIKV by targeting their NS2B–NS3 protease.