PURIFICATION AND CHARACTERIZATION OF A FIBRINOGENASE FROM VIPERA-LEBETINA (DESERT ADDER) VENOM

A fibrinogenase from Vipera lebetina venom was isolated by gel filtration in a Superose 12 column prep grade HR 16/50 and by ion-exchange in a Mono Q HR 5/5 column. The purified enzyme, which was obtained with a yield of 8 mg from 60 mg of crude venom, is a glycoprotein having an isoelectric point of 5.9 +/- 0.1 and a mol. wt of 26,000 +/- 1000 as estimated by SDS-PAGE. The biochemical characterization of the enzyme revealed that it hydrolyzes readily the B-beta chain of fibrinogen and the A-alpha chain as well as fibrin and casein. Over a pH range from 4 to 11 the enzyme was not inactivated by a 20 min treatment at 90-degrees-C. The isolated fibrinogenase is inhibited by ethylenediamine tetraacetic acid, dithiothreitol and L-cysteine but not by phenylmethylsulfonyl fluoride. On the other hand, it is activated by Ca2+ and Mg2+. Purified fibrinogenase up to a dose of 100-mu-g/mouse shows no toxicity and has no hemorrhagic activity.