Pantinin-Derived Peptides against Veterinary Herpesviruses: Activity and Structural Characterization

Animal viral infections represent a growing public health concern, as animals serve as reservoirs for pathogens, threatening food safety, biodiversity, and human health. In response, novel antiviral strategies are urgently needed. This study investigates the antiviral activity and structural properties of two antimicrobial peptides, pantinin-1 and pantinin-2, both derived from the venom of the scorpion Pandinus imperator, against caprine herpesvirus 1 (CpHV-1) and bovine herpesvirus 1 (BoHV-1). The results obtained from the plaque reduction assay and the quantitative real-time polymerase chain reaction (PCR) indicate that synthetic pantinin-mimetic peptides exhibited potent antiviral effects at concentrations ranging from 6–25 µM, impairing viral infectivity through direct virucidal action and inhibition of the viral entry and fusion with host cell. To characterize their structural behavior, nuclear magnetic resonance spectroscopy is performed in aqueous and membrane-mimetic environments (trifluoroethanol (TFE)/H₂O). In aqueous solution, both peptides predominantly adopted random coil conformations, with pantinin-2 showing greater secondary structure propensity. In TFE/H₂O, both peptides transitioned to α-helical structures, which are often associated with membrane interaction and antiviral activity. These findings demonstrate that pantinin-1 and pantinin-2 possess promising antiviral properties, supporting their potential development as therapeutic agents against herpesviruses and other animal viral infections.