CARACTERIZACIÓN BIOQUÍMICA DE UNA FRACCIÓN CON ACTIVIDAD HEMORRÁGICA OBTENIDA DEL VENENO DE Bothriopsis medusa (SERPENTES, VIPERIDAE).

The Venezuelan forest-pitviper, Bothriopsis medusa, popularly known locally as "mapanare viejita", is considered an endemic species in Venezuela. Very little is known about the haemorrhagic effects produced by the venom of this snake, so the main objective of this study was to perform the isolation and biochemical characterization of a fraction of its venom with haemorrhagic activity, using biochemical methods. The crude venom was fractionated by molecular exclusion chromatography. Then, both the crude venom and the fractions were assayed for haemorrhagic activity, and finally SDS-PAGE chromatogrbaphy was performed. Fraction 2 (F2) was chosen because of its high haemorrhagic action. Subsequently, anion exchange chromatography was carried out in order to purify the proteins with higher haemorrhagic activity. The elution profile revealed ten well-defined peaks, in which it was decided to analyse the anionic fraction 4 (FA4 haemorrhagic fraction) by a) SDS-PAGE, b) haemorrhagic activity, c) protein determination, d) fibrinogenolytic activity and e) gelatinolytic activity. The electrophoretic profile of F2 showed proteins with molecular weight between ~116 to 31 kDa and FA4 ~ 35, 45, 60 and 98 kDa. This fraction exhibited a haemorrhagic area in the skin. The fibrinogenolytic tests showed a total proteolysis of the a chain, intense of the ß chain, both at 24 hours, as well as a total proteolysis of the γ chain at 48 hours. Finally, it is possible to suggest the presence of enzymes with serine and metalloprotease activity, responsible for generating the skin and systemic haemorrhagic picture in individuals who suffer an accident caused by Bothriopsis medusa snake. [ABSTRACT FROM AUTHOR]