Scorpion venom peptide promotes immunity and survival of litopenaeus vannamei through its antibacterial effect on vibrio parahaemolyticus

introduction: Antimicrobial peptides (AMPs) derived from Scorpion venom have emerged as promising candidates for combating bacterial infections due to their potent activity and unique mechanisms of action. This study focuses on three 13-amino acid peptides (BMKN1, BMKN2, and BMKN2-7). Mesobutus Martensii. The aim is to elucidate their structural features, antibacterial and immunomodulatory effects litopenaeus vannamei I’m infected Vibrio parahaemolyticus (VP).

method: Peptides were synthesized and comprehensively characterized for amphiphilic α-helical structure, net charge, and hydrophobicity. Their antibacterial mechanisms were investigated using a series of assays including membrane permeability (internal/outer membrane breakdown), membrane depolarization, quantification of reactive oxygen species (ROS), and measurement of ATPase activity. An in vivo challenge experiment was carried out to assess the survival rate of L. vannamei infected with VP. Furthermore, immunoenzyme activity (phenoloxidase) [PO]Component 3 [C3]and inflammatory/antibiotic gene expression levels (TNF-α, IL-1β, TGF-β, ALF, CRUS). Furthermore, intestinal transcriptome profiling was performed to identify activated immune pathways.

result: All peptides showed membrane targeting activity: BMKN2-7 showed excellent outer membrane penetration and depolarization, whereas BMKN1 was effective due to inner membrane disruption and ROS induction. In vivo, all peptides significantly improve the survival rate of VP-infected shrimp (P <0.01）、BMKN2-7≈BMKN1> BMKN2 was effective. Immunomodulation was evident through increased PO and C3 activity (P <0.05) and reduced expression of inflammatory cytokines and antimicrobial genes (P <0.05). Transcriptome analysis revealed BMKN2-7-activated PPAR, AMPK, and FOXO signaling pathways.

Discussion: The amphiphilic α-helical structure of these peptides is fundamental to their membrane-destructive activity. Enhanced outer membrane targeting of BMKN2-7 may correlate with hydrophobicity and structural modifications that optimize charge distribution. Differential effects on immunomodulation, such as broad pathway activation of BMKN2-7 and selective ROS induction of BMKN1, indicate structure-dependent functional divergence. These findings highlight the possibility of tailored scorpion venom peptides as double-acting agents against bacterial infections and immune dysregulation.

Zeng, L., Sun, Y., Zhang, H., Yi, X., Du, R., Chen, Z. , & Wang, Q. (2025). Scorpion venom peptide promotes immunity and survival of litopenaeus vannamei through its antibacterial action against Vibrio paraflyflies hemolysis. Frontiers of Immunology, 161551816. https://doi.org/10.3389/fimmu.2025.1551816