Isolation and characterization of five fibrin(ogen)olytic enzymes from the venom of Philodryas olfersii (green snake)

Abstract

M. T. Assakura, A. P. Reichl and F. R. Mandelbaum. Isolation and characterization of five fibrin(ogen)olytic enzymes from the venom of Philodryas olfersii (green snake). Toxicon 32, 819–831, 1994.—Five distinct fibrin(ogen)olytic proteinases PofibC 1, C 2, C 3, H and S were isolated by gel filtration and ion-exchange chromatographies. PofibC 1, C 2, C 3 and H are metalloproteinases inhibited by ethylenediamine tetracetic acid (EDTA) or 1,10-phenanthroline. Only PofibH had hemorrhagic activity. PofibS is a serine proteinase, inhibited by phenylmethylsulfonyl fluoride (PMSF) or Torresea cearensis trypsin inhibitor (TCTI). All five enzymes were inhibited by dithiothreitol (DTT) or dithioerythritol (DTE). PofibC 1 and C 2 presented the same mol. wt of 47,000 and are acidic proteins of p I 6.2. PofibC 3 is a basic proteinase of p I 8.5 and mol. wt 45,000. The hemorrhagic proteinase PofibH had a mol. wt of 58,000 and p I of 4.6 and PofibS had a mol. wt of 36,000 and p I of 4.5. The five proteinases degraded fibrin and fibrinogen. PofibC 1, C 2, C 3 and H degraded preferentially Aα-chains while PofibS cleaved concomitantly Aα and Bβ-chains of fibrinogen. None of these enzymes cleaved the γ-chain of fibrinogen. When correlated with the thrombin delay time, the most active was PofibS, while PofibH and PofibC 1 showed almost no activity. The proteinases also differed in the peptide cleavage of B-chain of insulin. Philodryas olfersii venom promoted in vivo a loss of the circulant plasma fibrinogen, as was observed in experiments with rats.