Identification of Bothrojaracin-like proteins in snake venoms from Bothrops species and Lachesis muta

Bothrojaracin, a 27 kDa protein isolated from Bothrops jararaca venom, form s a non-covalent complex with thrombin, thus blocking its activity. We have previously identified a bothrojaracin-like protein in B. alternatus venom [Castro, H.C., Dutra, D.L.S., Oliveira-Carvalho, A.L., Zingali, R.B., 1998. Bothroalternin, an inhibitor of thrombin from the venom of Bothrops altern atus. Toxicon 36, 1903-1912]. In this report, we have examined snake venoms from six different Bothrops species (B. atrox, B cotiara, B. jararacussu, B. moojeni and B. neuwiedi), from Lachesis muta and from Crotalus durissus terrificus for the presence of bothrojaracin-like proteins, which we define here as 27 kDa proteins that are immunologically related to bothrojaracin and that inhibit thrombin-induced platelet aggregation. The immunological a nalysis of these venoms by different techniques indicated the existence of at least one protein recognized by anti-bothrojaracin serum. ELISA confirme d the greater bothrojaracin immunoreactivity of proteins present in B. atro x and B. cotiara as compared to other Bothrops species. Smaller amounts of proteins related to bothrojaracin were found in L. muta venom and were abse nt from the venom of C. d. terrificus. Our results thus suggest that bothro jaracin-like proteins are widely distributed among Bothrops genera. (C) 199 9 Elsevier Science Ltd. All rights reserved.