title: In vivo characterization of Lopap, a prothrombin activator serine protease from the Lonomia obliqua caterpillar venom.
abstract: Increasing occurrence of hemorrhagic syndrome in man, caused by contact with Lonomia obliqua caterpillars, has been reported in Southern Brazil in the past 10 years. The L. obliqua venom causes a severe consumptive coagulopathy, which can lead to hemorrhagic syndrome. L. obliqua prothrombin activator protease (Lopap) is a 69-kDa prothrombin activator serine protease isolated from L. obliqua caterpillar bristle extract, which is able to evoke thrombus formation, unclottable blood, and fibrinogen depletion when injected into the blood stream of rats. The purified protein generated thrombin from prothrombin, able to clot purified human fibrinogen and plasma. A decrease in platelet count and inhibition of collagen-induced platelet aggregation were observed, as well as leukocyte infiltration in the lungs. In addition, we observed congestion and hemorrhage in renal glomeruli and necrosis in renal distal tubules. These data support the hypothesis that Lopap contributes to the clinical syndrome caused by human contact with L. obliqua, most probably through prothrombin activation, resulting in a consumption coagulopathy.
authors.affiliation: Laboratory of Biochemistry and Biophysics, Butantan Institute, Center for Applied Toxinology, CEPID-FAPESP, São Paulo, Brazil.
authors.forename: C V
authors.initials: CV
authors.lastname: Reis
authors.forename: S H
authors.initials: SH
authors.lastname: Farsky
authors.forename: B L
authors.initials: BL
authors.lastname: Fernandes
authors.forename: M L
authors.initials: ML
authors.lastname: Santoro
authors.forename: M L
authors.initials: ML
authors.lastname: Oliva
authors.forename: M
authors.initials: M
authors.lastname: Mariano
authors.forename: A M
authors.initials: AM
authors.lastname: Chudzinski-Tavassi
mesh_terms: D000818:Animals; D001180:Arthropod Venoms / Q000302:isolation & purification / Q000494:pharmacology; D001777:Blood Coagulation / Q000187:drug effects; D006801:Humans; D007668:Kidney / Q000098:blood supply / Q000187:drug effects / Q000473:pathology; D007814:Larva; D007915:Lepidoptera; D008168:Lung / Q000098:blood supply / Q000187:drug effects / Q000473:pathology; D008297:Male; D008833:Microcirculation / Q000187:drug effects / Q000473:pathology; D018715:Microscopy, Video; D009928:Organ Specificity; D010976:Platelet Count; D051381:Rats; D017208:Rats, Wistar; D012697:Serine Endopeptidases / Q000302:isolation & purification / Q000494:pharmacology*; D013927:Thrombosis / Q000139:chemically induced
chemical_list: D001180:Arthropod Venoms; C119835:Lonomia obliqua prothrombin activator protease; D012697:Serine Endopeptidases