Peptides designed based on 3C substrates exhibit antiviral efficacy in vivo.

Enteroviruses are a large group of positive-sense single-stranded RNA viruses including numerous human pathogens such as enterovirus A71 (EV-A71), coxsackieviruses, and echoviruses. The diseases caused by these enteroviruses pose a significant threat to global public health. The 3C protein is a crucial protease in enteroviruses, responsible for cleaving the viral polyprotein into individual active proteins. This process is essential for viral replication and pathogenesis, making 3C an attractive target for the development of anti-enteroviral drugs. In this study, we designed and screened peptides based on the sequences of several substrates of the 3C protease, aiming to impact the function of the 3C protease and thereby exert antiviral effects. Ultimately, we obtained a peptide with good antiviral activity at the cellular level, which we named vp23. This peptide effectively disrupted the protease activity of 3C, provided significant in vivo protection against EV-A71, and possessed strong antiviral effects against multiple enteroviruses such as EV-A71, Coxsackievirus A16 (CV-A16), and Echovirus 11 (Echo 11). Taken together, our results suggest that targeting 3C proteases using rationally designed peptides is an effective antiviral strategy against enteroviruses.