Purification and biochemistry characterization of a procoagulant factor of Lonomia oblique venom

Author(s)

Renata Pereira

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2006-12-19

Examining board members

Gilberto De Nucci; Sergio Marangoni; Joyce Maria Annichino Bizzacchi; Soraia Katia Pereira Costa; José Carlos Cogo

• Advisor: Gilberto De Nucci

Abstract

Since 1986 accidents caused by contact with caterpillars of butterflies of the Lonomia obliqua species comes being notified in the South Region of Brazil. The human envenoming for this species results in alterations of the coagulation system, characterizing a disseminated intravascular coagulation, associated to a severe fibrinolytic syndrome. Studies had demonstrated that the venom of the Lonomia obliqua contains a factor X and a prothrombin activator. An activator protein of prothrombin, called LOPAP (¿Lonomia obliqua prothrombin activator protease¿) was isolated and biochemist and physiologically characterized. This enzyme is a serine protease of 69 kDa. When tested in vivo, the LOPAP leads to thrombus formation, microvasculary and pulmonary hemorrhage, unclottable blood and leukocyte infiltration in the lungs at rats. In this work, through chromatography of exclusion, followed by phase reverse chromatography (HPLC), it was isolated a 20745.7 Da protein of the spicules extract of L. obliqua. During the process, it was evaluated the purified human factor X activator activity in vitro, through kinetic assay with the chromogenic substrate use. The isolated protein presented factor Xa like activity and presented immunorreactivity with the antilonomic serum, produced by Butantan Institute. Using techniques applied to the proteomic studies, it was determined the amino acid sequence of the protein with factor Xa like activity. It is a new protein, not yet sequenced, which has large identity with lipocalins family protein (AU)