Use of a synthetic biosensor for neutralizing activity-biased selection of monoclonal antibodies against atroxlysin-I, an hemorrhagic metalloproteinase from Bothrops atrox snake venom

• Published in: PLoS neglected tropical diseases 2014-04, Vol.8 (4), p.e2826-e2826
• Main Authors: Schneider, Francisco Santos, Nguyen, Dung Le, Castro, Karen Larissa, Cobo, Sandra, Machado de Avila, Ricardo Andrez, Ferreira, Nivia de Assis, Sanchez, Eladio Flores, Nguyen, Christophe, Granier, Claude, Galéa, Pascale, Chávez-Olortegui, Carlos, Molina, Franck
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Monoclonal - immunology; Antibodies, Monoclonal - isolation & purification; Antibodies, Neutralizing - immunology; Antibodies, Neutralizing - isolation & purification; Antitoxins - immunology; Antitoxins - isolation & purification; Biology and Life Sciences; Biosensing Techniques - methods; Bothrops; Fluorescence Resonance Energy Transfer; Humans; Identification and classification; Immune response; Life Sciences; Mass Screening - methods; Metalloendopeptidases - immunology; Monoclonal antibodies; Peptides; Peptides - chemical synthesis; Physiological research; Properties; Proteases; Snake Venoms - immunology; Snakes; South America; Venom
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0002826

The snake Bothrops atrox is responsible for the majority of envenomings in the northern region of South America. Severe local effects, including hemorrhage, which are mainly caused by snake venom metalloproteinases (SVMPs), are not fully neutralized by conventional serum therapy. Little is known about the immunochemistry of the P-I SVMPs since few monoclonal antibodies (mAbs) against these molecules have been obtained. In addition, producing toxin-neutralizing mAbs remains very challenging. Here, we report on the set-up of a functional screening based on a synthetic peptide used as a biosensor to select neutralizing mAbs against SVMPs and the successful production of neutralizing mAbs against Atroxlysin-I (Atr-I), a P-I SVMP from B. atrox. Hybridomas producing supernatants with inhibitory effect against the proteolytic activity of Atr-I towards the FRET peptide Abz-LVEALYQ-EDDnp were selected. Six IgG1 Mabs were obtained (named mAbatr1 to mAbatr6) and also two IgM. mAbatrs1, 2, 3 and 6 were purified. All showed a high specific reactivity, recognizing only Atr-I and B. atrox venom in ELISA and a high affinity, showing equilibrium constants in the nM range for Atr-I. These mAbatrs were not able to bind to Atr-I overlapping peptides, suggesting that they recognize conformational epitopes. For the first time a functional screening based on a synthetic biosensor was successfully used for the selection of neutralizing mAbs against SVMPs.