Purificação, caracterização bioquimica e funcional de uma serinoprotease (Uruprot) do veneno de Bothrops alternatus (Urutu)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

Snake venoms contain a high variety of toxic compounds and enzymes. Venom purified proteases are structurally dassified as serine proteases and metalloproteases, and showa potent effect on blood coagulation, acting on hemostasis, thrombosis, fibrinolysis and platelet aggregation. The aim of this work was the purification and characterization of a serine protease from the venom of Bothrops altematus snake, called Uruprot. Uruprot was purified in a two step chromatography: Sephadex G-75 and DEAE 5PW both in HPLC system. Its homogenity was monitored in SDS-PAGE and reversedphase C18 chromatography. In denaturing conditions, 0,1 M DTT, a band of 32 kDa apparent molecular mass was evidenced, suggesting that the protein consists in one polypeptidic chain. The two dimensional electrophoresis of Uruprot showed its isoelectric point at about 4,6, confirming the apparent molecular mass observed in SDS-PAGE. Uruprot s amino acid analysis composition showed a high concentration of glycine, threonine, phenylalanine, isoleucine, serine and glutamine and low levels of basic amino aCids, as histidine and arginine, ratifying the result obtained from bidimensional electrophoresis wich showed an acid pl. Uruprot showed a positive reaction when submitted to carbohydrate coloration indicating the presence of carbohydrate covalentely bound to its structure. The N-terminal sequence homology study showed a consensus sequence (WGGDECNINEHR-LVAI) and indicated a high homology with serine proteinase TSV-PA (94%), KLE 11 (94%), Ancrod (92%), and others. Uruprot did not induce platelet aggregation but inhibits erytrocytes agglutination in the presence of ristocetin, in a minimum concentration of 10llg/mL. Ali the results obtained indicates that Uruprot is a serine protease plasminogen activator, however, the role of "in vivo" activity of venom serine proteases in envenomation remains unclear. Additional studies are necessary to provide more information about this enzyme group

ASSUNTO(S)

cobra venenosa - veneno

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