ISOLATION AND CHARACTERIZATION OF 5 FIBRIN(OGEN)OLYTIC ENZYMES FROM THE VENOM OF PHILODRYAS-OLFERSII (GREEN SNAKE)

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 pI 6.2. PofibC(3) is a basic proteinase of pI 8.5 and mol. wt 45,000. The hemorrhagic proteinase PofibH had a mol. wt of 58,000 and pI of 4.6 and PofibS had a mol. wt of 36,000 and pI of 4.5. The five proteinases degraded fibrin and fibrinogen. PofibC(1), C-2, C-3 and H degraded preferentially A alpha-chains while PofibS cleaved concomitantly A alpha and B beta-chains of fibrinogen. None of these enzymes cleaved the gamma-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.