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 an d S were isolated by gel filtration and ion-exchange chromatographies. PofibC(1), C-2, C-3 and H are metalloproteinases inhibited by ethylen ediamine tetracetic acid (EDTA) or 1,10-phenanthroline. Only PofibH ha d hemorrhagic activity. PofibS is a serine proteinase, inhibited by ph enylmethylsulfonyl fluoride (PMSF) or Torresea cearensis trypsin inhib itor (TCTI). All five enzymes were inhibited by dithiothreitol (DTT) o r 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 pro teinase of pI 8.5 and mol. wt 45,000. The hemorrhagic proteinase Pofib H 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 fibrinoge n. PofibC(1), C-2, C-3 and H degraded preferentially A alpha-chains wh ile PofibS cleaved concomitantly A alpha and B beta-chains of fibrinog en. None of these enzymes cleaved the gamma-chain of fibrinogen. When correlated with the thrombin delay time, the most active was PofibS, w hile PofibH and PofibC(1) showed almost no activity. The proteinases a lso differed in the peptide cleavage of B-chain of insulin. Philodryas olfersii venom promoted in vivo a loss of the circulant plasma fibrin ogen, as was observed in experiments with rats.