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Isolation and structural characterization of a new fibrin(ogen)olytic metalloproteinase from Bothrops moojeni snake venom

2007; Elsevier BV; Volume: 51; Issue: 4 Linguagem: Inglês

10.1016/j.toxicon.2007.11.017

1879-3150

Carolina P. Bernardes, Norival A. Santos‐Filho, Tássia R. Costa, Mário S.R. Gomes, Fernanda Silva Torres, Júnia de Oliveira Costa, Márcia Helena Borges, Michael Richardson, Daniel M. Santos, Adriano M.C. Pimenta, Maria I. Homsi-Brandeburgo, Andreimar M. Soares, Fábio de Oliveira,

Rabies epidemiology and control

A proteinase, named BmooMPα-I, from the venom of Bothrops moojeni, was purified by DEAE-Sephacel, Sephadex G-75 and heparin-agarose column chromatography. The enzyme was purified to homogeneity as judged by its migration profile in SDS–PAGE stained with coomassie blue, and showed a molecular mass of about 24.5 kDa. Its complete cDNA was obtained by RT-PCR and the 615 bp codified for a mature protein of 205 amino acid residues. The multiple alignment of its deduced amino acid sequence and those of other snake venom metalloproteinases showed a high structural similarly, mainly among class P-IB proteases. The enzyme cleaves the Aα-chain of fibrinogen first, followed by the Bβ-chain, and shows no effects on the γ-chain. On fibrin, the enzyme hydrolyzed only the β-chain, leaving the γ-dimer apparently untouched. It was devoid of phospholipase A2, hemorrhagic and thrombin-like activities. Like many venom enzymes, it is stable at pH values between 4 and 10 and stable at 70 °C for 15 min. The inhibitory effects of EDTA on the fibrinogenolytic activity suggest that BmooMPα-I is a metalloproteinase and inhibition by β-mercaptoethanol revealed the important role of the disulfide bonds in the stabilization of the native structure. Aprotinin and benzamidine, specific serine proteinase inhibitors, had no effect on BmooMPα-I activity. Since the BmooMPα-I enzyme was found to cause defibrinogenation when administered i.p. on mice, it is expected that it may be of medical interest as a therapeutic agent in the treatment and prevention of arterial thrombosis.