Anti-Metalloprotease P-I Single-Domain Antibodies: Tools for Next-Generation Snakebite Antivenoms.

Area of Science:

• Immunology
• Biochemistry
• Pharmacology

Background:

• The global antivenom crisis necessitates novel antivenoms with high efficacy, broad neutralization, safety, and cost-effectiveness.
• Camelid single-domain antibodies (VHHs) offer advantages like high affinity, tissue penetration, and genetic manipulability for antivenom development.

Purpose of the Study:

• To select and characterize VHHs active against the metalloprotease BjussuMP-II from *Bothrops jararacussu* snake venom.
• To evaluate the therapeutic potential of these VHHs in neutralizing venom toxicity and their suitability for next-generation antivenoms.

Main Methods:

• Isolation of BjussuMP-II and immunization of a camelid to construct a recombinant phage library.
• Biopanning, ELISA, sequencing, *in vitro* toxicity neutralization assays, circular dichroism spectroscopy, and *in silico* molecular docking.

Main Results:

• Fifty-two percent of selected clones recognized BjussuMP-II; seven sequence profiles were identified.
• One clone (VHH61) showed specificity for the *Bothrops* genus and neutralized BjussuMP-II toxicity *in vitro*.
• VHH61 demonstrated a robust secondary structure (Tm = 56.4°C) and potential interaction with critical toxin regions via molecular docking.

Conclusions:

• Anti-BjussuMP-II VHHs exhibit promising neutralizing capacity against *Bothrops jararacussu* venom components.
• These VHHs possess favorable structural stability and specific binding characteristics.
• The findings support the development of VHH-based antivenoms as a potential solution to the antivenom crisis.