Enteroviruses have been a historical concern since the identification of polioviruses in humans. Wild polioviruses have almost been eliminated, while multiple species of non-polio enteroviruses and their variants co-circulate annually. To date, at least 116 types have been found in humans and are grouped into the species Enterovirus A–D and Rhinovirus A–C. However, there are few available antiviral drugs, especially with a universal pharmaceutical effect. Here, we demonstrate that peptide P25 from EV-D68 has broad antiviral activity against EV A–D enteroviruses in vitro. P25, derived from the HI loop and β-I sheet of VP1, operates through a conserved hydrophilic motif -R---K-K--K- and the hydrophobic F near the N-terminus. It could prevent viral infection of EV-A71 by competing for the heparan sulfate (HS) receptor, binding and stabilizing virions by suppressing the release of the viral genome. P25 also inhibited the generation of infectious viral particles by reducing viral protein synthesis. The molecular docking revealed that P25 might bind to the pocket opening area, a potential target for broad-spectrum antivirals. Our findings implicate the multiple antiviral effects of peptide P25, including blocking viral binding to the HS receptor, impeding viral genome release, and reducing progeny particles, which could be a novel universal anti-enterovirus drug candidate.

Enteroviruses (EVs and RVs) are prevalent worldwide and cause various diseases in humans, of which the VP1-pocket is a target of antivirals, with a lipid molecule as a pocket factor to stabilize the virion. However, the characterization of the structure of the VP1-pocket in EVs is poor. Here, we compared the published capsid crystals of EVs and RVs and proposed a structural framework for the VP1-pocket: Frame 1–4, which is located at the CD loop, GH loop, and C-terminus, presenting with an outward opening appearance or not. The non-outward viral strains—CVB3, Echo 11, RV-A81, and RV-B70—are more thermally stable, with a breakpoint temperature (B.T.) of 51~62 °C for genome releasing, which is 4~10 °C higher than its outward temperature of 41~47 °C, and infectivity preservation when treated at 50 °C for 3 min. Its outward versus non-outward opening is correlated significantly with the B.T. for genome release (r = −0.90; p = 0.0004) and infectivity (r = −0.82, p = 0.0039). The energy of Frames 1, 2, and 4, including Van der Waals attractive and repulsive interactions and hydrogen bonds, showed significant correlations with the B.T. (r = −0.67, 0.75, and −0.8; p = 0.034, 0.013, and 0.006, respectively). These characters of the VP1-pocket could be predictors for virion thermostability and aid in the development of vaccines or antivirals.