Venom composition of the Iberian adder (Vipera seoanei) from northern Portugal reveals limited sex and size variation

  Venom composition of the Iberian adder (Vipera seoanei) from northern Portugal reveals limited sex and size variation Abstract Snake venom is a complex and dynamic ecological trait, with high potential for intraspecific variation. In this study, the venom composition of the Iberian adder ( Vipera seoanei ) from the Peneda Mountains of northern Portugal was investigated to explore whether venom varies with body size and sex. Venom proteomes from six individuals representing juvenile, subadult, and adult males and females were characterised using LC–MS/MS, while individual variation was assessed from SDS–PAGE profiles of 18 snakes. LC–MS/MS identified 144 proteins, dominated by phospholipases A 2 (PLA 2 ), snake venom serine proteases (svSP), and C-type lectin-related proteins (CTL). Descriptive comparisons revealed contrasting individual profiles, particularly between the juvenile male, characterised by high svSP and svMP abundance, and the juvenile female, characterised by high ...

Conserved Enzymatic Peptides in Bitis arietans Venom Revealed by Comparative Proteomics: Implications for Cross-Reactive Antibody Targeting

 

Conserved Enzymatic Peptides in Bitis arietans Venom Revealed by Comparative Proteomics: Implications for Cross-Reactive Antibody Targeting

Abstract

Snakebite envenoming remains a critical public health issue, and the molecular variability of venoms limits the cross-species efficacy of conventional antivenoms. Here, we conducted a comparative proteomic analysis of Bitis arietans venom to identify conserved peptide regions derived from enzymatic toxins and evaluate their potential relevance for complementary immunotherapeutic applications. Enzyme-enriched venom fractions were isolated through sequential affinity and ion-exchange chromatography and were subsequently characterized using fluorogenic FRET substrates and inhibitor assays. LC–MS/MS analysis identified 1099 proteins and revealed 36 conserved peptides within snake venom metalloproteinases (SVMPs), serine proteases (SVSPs), and phospholipase A2 (PLA2), particularly located near catalytic residues and structurally essential motifs such as the HExxHxxGxxH zinc-binding site in SVMPs, the His-Asp-Ser catalytic triad in SVSPs, and the Ca2+-binding loop in PLA2, across Viperidae venoms. These conserved regions were also observed in homologous toxin isoforms from additional Viperidae genera, supporting the evolutionary conservation of key functional domains. While sequence conservation alone does not guarantee neutralization capacity, the identified regions represent strong candidates for structural epitope mapping and targeted antibody development. This study provides a peptide-level framework for advancing complementary antibody-based therapies designed to broaden cross-species toxin recognition, reduce antivenom dosage requirements, and improve clinical outcomes in snakebite envenoming.

Godoi, K. S., Portaro, F. C., Spencer, P. J., Vigerelli, H., & Silva, W. D. (2026). Conserved Enzymatic Peptides in Bitis arietans Venom Revealed by Comparative Proteomics: Implications for Cross-Reactive Antibody Targeting. International Journal of Molecular Sciences, 27(3), 1431. https://doi.org/10.3390/ijms27031431