title: Lonofibrase, a novel alpha-fibrinogenase from Lonomia obliqua caterpillars.
abstract: Envenomation caused by Lonomia obliqua caterpillars is an increasing problem in Southern Brazil. The clinical profile is characterized by a profound hemorrhagic disorder. In the present study, we describe the characterization of a fibrin(ogen)olytic factor (lonofibrase) isolated from a venomous secretion of the caterpillars. The crude extract showed a dose-dependent inhibitory effect in the rate of thrombin-induced fibrinogen clotting and produced fragmentation of fibrinogen. Isolation of the fibrin(ogen)olytic enzyme was achieved by combining ion exchange chromatography followed by gel filtration in a fast protein liquid chromatography (FPLC) system. A single 35-kDa band was identified and the isolated enzyme named lonofibrase. Lonofibrase rapidly degrades Aalpha and Bbeta chains of fibrinogen, also being able to cleave fibrin in a distinct way from that observed with plasmin. The presence of lonofibrase with both fibrinogenolytic and fibrinolytic activities in L. obliqua secretion is coherent with the severe hemorrhagic clinical profile resulting from envenomation caused by these insects.
authors.affiliation: Universidade Federal do Rio Grande do Sul, Centro de Biotechnologia, Av. Bento Goncalves 9500, PO Box 15005, Porto Alegre 91501-970, Brazil.
authors.forename: Antônio Frederico Michel
authors.initials: AF
authors.lastname: Pinto
authors.forename: Ricardo
authors.initials: R
authors.lastname: Dobrovolski
authors.forename: Ana Beatriz Gorini
authors.initials: AB
authors.lastname: Veiga
authors.forename: Jorge Almeida
authors.initials: JA
authors.lastname: Guimarães
mesh_terms: D000818:Animals; D001180:Arthropod Venoms / Q000201:enzymology*; D010450:Endopeptidases / Q000302:isolation & purification* / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism; D005342:Fibrinolysis / Q000187:drug effects; D006470:Hemorrhage; D007700:Kinetics; D007814:Larva; D009036:Moths
chemical_list: D001180:Arthropod Venoms; D005340:Fibrinogen; D010450:Endopeptidases; C495707:lonofibrase