Antibodies against a single fraction of Micrurus dumerilii venom neutralize the lethal effect of whole venom. (1st February 2023)

• Record Type: Journal Article
• Authors: Gómez-Robles, Jeisson; Rey-Suárez, Paola; Pereañez, Jaime Andrés; Lomonte, Bruno; Núñez, Vitelbina
• Is Part Of: Toxicology letters. Volume 374(2023)
• Page Start: 77
• Page End: 84
• Publication Date: 2023-02-01
• Subjects: Coral snakes -- Venom -- Micrurus dumerilii -- Phospholipase A2 -- Neutralization -- Antibody; Toxicology -- Periodicals; 363.179
• DOI: 10.1016/j.toxlet.2022.12.005
• Languages: English
• ISSNs: 0378-4274

Abstract

Abstract: The coralsnake Micrurus dumerilii (Elapidae) is reported to cause envenomings of medical importance. Previous studies characterized the protein composition of its venom, with phospholipase A2 (PLA2 ) proteins the most abundant. However, it is unknown which venom components are responsible for its lethal toxicity. Fractionation of M. dumerilii venom from Colombia was carried out using RP-HPLC and each fraction was screened for lethal effect in mice at a dose of 20 μg by intraperitoneal route. Results showed that only one fraction, F9, was lethal. This fraction displayed PLA2 activity, induced indirect hemolysis in vitro, as well as edema and myotoxicity in vivo. SDS-PAGE of unreduced F9 evidenced two bands of 8 and 15 kDa, respectively, consistent with the detection of proteins with masses of 13, 217.77 Da, 7144.06 Da, and 7665.55 Da. Tryptic digestion of F9 followed by nESI-MS/MS revealed peptide sequences matching proteins of the three-finger toxin (3FTx) and PLA2 families. Immunization of a rabbit with F9 proteins elicited antibody titers up to 1:10, 000 by ELISA. After serum fractionation with caprylic acid, the obtained IgG was able to neutralize the lethal effect of the complete venom of M. dumerilii using a challenge of 2 ×LD50 at the IgG/venom ratio of 50:1 (w/w). In conclusion, present results show that the lethal effect of M. dumerilii venom in mice is mainly driven by one fraction which contains 3FTx and PLA2 proteins. The antibodies produced against this fraction cross-recognized other PLA2 s and neutralized the lethal effect of whole M. dumerilii venom, pointing out to the potential usefulness of F9 as a relevant antigen for improving current coral snake antivenoms. Graphical Abstract: ga1 Highlights: Out of 32 M. dumerilii venom chromatographic fractions, only one (F9) was lethal. F9 fraction contains proteins of the 3FTx and PLA2 families. Antibodies produced against F9 recognized M. dumerilii and M.mipartitus PLA2 s. Antibodies produced against F9 neutralized the lethal effect of whole M. dumerilii venom.