Broad-Spectrum Antiviral and Antibacterial Activity of the Scorpion Venom Peptide HP1090

HP1090 is a short, cationic, amphipathic peptide derived from scorpion venom and previously described as a membrane-active antiviral compound. Here, we primarily characterize the antiviral activity of HP1090 and assess whether additional antibacterial effects are consistent with membrane-disruptive properties. Chemically synthesized HP1090 exhibited dose-dependent virucidal activity against multiple enveloped viruses, including herpes simplex virus type 1 and 2 (HSV-1, HSV-2), human immunodeficiency virus type 1 (HIV-1), and Zika virus (ZIKV), with IC₅₀ values ranging from 14.7 to 56.1 µg/mL. No activity was observed against the non-enveloped human rhinovirus 14 (HRV14), suggesting strict dependence on a viral lipid envelope. Consistent with a membrane-targeting mechanism, HP1090 induced rapid and concentration-dependent permeabilization of virus-like liposomes. HP1090 also displayed antibacterial activity against selected clinically relevant pathogens in agar-based growth inhibition assays. However, antibacterial effects required substantially higher concentrations (>125 µg/mL) and varied between bacterial species, with some strains showing little or no susceptibility. Membrane permeabilization assays in Listeria monocytogenes demonstrated disruption of bacterial membrane integrity as a contributing mechanism. No cytotoxicity was observed on mammalian cell lines at effective antiviral concentrations. Together, these findings establish HP1090 as a membrane-active venom peptide and, by linking envelope-dependent viral inactivation with bacterial membrane permeabilization, support a shared biophysical mode of action relevant to the development of membrane-targeting anti-infectives.