For the best treatment of the bite of this snake, it was suggested that therapeutic should be associated with anti-crotalic horse antivenom. Later, experiments were conducted to confirm that the administration of both the anti-bothropic and anti-crotalic horse antivenom provided a more effective neutralization for the myotoxic, coagulant and/or lethal activities than one antivenom used alone ( de Roodt et al., 1999 and Queiroz
et al., 2008). This was not restricted only with bothropic-crotalic antivenom since it was recently observed for venom from Australian snake species ( O’Leary and Isbister, 2009). Other immunochemical studies using rabbit antibodies against a synthetic peptide (residues 1–15) of BthTX-I (Angulo et al., 2001) and an anti-NN-XIa-PLA2 from Naja naja venom ( Basavarajappa et al., 1993) showed that the enzymatic activity of these PLA2s was RG7422 ic50 inhibited in a dose-dependent manner by antibodies. However, the lethal and neurotoxic symptoms were not neutralized selleck compound in experimental animals ( Basavarajappa et al., 1993). Further studies have demonstrated cross-reactivity between BthTX-I and the crotoxin
of Crotalus durissus cascavella, but the common and specific antigenic determinants were not identified ( Oshima-Franco et al., 2001 and Beghini et al., 2007). Overall, the mechanisms associated with the capacity to neutralize myotoxic and anticoagulant activities of snake venoms remain unknown along with the observed protective synergic effects of combining therapeutic antivenom. In this study, we report the identification and structural characterization of the linear B-cell epitopes of the three PLA2s from B. jararacussu snake venom recognized by neutralizing anti-bothropic and anti-crotalic commercial horse antivenom. The results suggest that the best performance of the monovalent anti-crotalic antivenom to neutralize B. jararacussu PLA2s may be due to the recognition of different epitopes Adenosine triphosphate rather than cross-reactivity or other factors such as the affinity of the antibodies. Our observations reinforce the importance of defining the mechanisms leading to the
neutralization of the highly toxic proteins in venom by commercial antivenom to drive production of more protective treatments. Amino acids for peptide synthesis were from Calbiochem-Novabiochem Corp. (San Diego, CA, USA). Super SignalR West Pico chemiluminescent substrate was from Pierce Biotechnology (Rockford, IL, USA). Amino-PEG500-UC540 cellulose membranes were obtained from Intavis Bioanalytical Instruments (Koeln, Germany). Pyperidine, acetonitrile and trifluoracetic acid were from Fluke. A peroxidase-labeled rabbit anti-horse immunoglobulin serum was from KPL (Gaithersburg, MD, USA). Bovine serum albumin, 3,3,5,5′ tetramethylbenzidine (TMB) and Tween 20 were obtained from Sigma–Aldrich Corp. (St. Louis, MO, USA). Amicon centricon 10 filters were from Millipore (Billerica, MD, USA).