Antivenom activity of opossum (Didelphys marsupialis) serum fractions against Uracoan rattlesnake (Crotalus vegrandis Klauber, 1941) venom.

In this work, we have found strong evidence for the presence of an opossum serum which is highly proficient in inactivating the neurotoxic fractions of Uracoan rattlesnake (Crotalus vegrandis) venom. Analyses of strained electrophoretic patterns of SDS gels run in non-reducing conditions revealed a small group of antivenom proteins in 0.1 M DEAE cellulose fraction that was not found in 0.05 M, 0.02 M, 0.25 M and 0.3 M NaCl ionic strength. Neutralizing activities to mapanare (Bothrops lanceolatus) venom have been already described but this is the first time that opossum serum anticrotalus activity is found. In spite of having preliminary results, we wish to make the corresponding report, while we accomplish the purification of the neutralizing component. One protein isolated from opossum serum or a synthetic peptide based on the aforementioned protein would probably be very useful in medical management of Crotalus vegrandis accidents.