Recombinant production of fibrinogenase IV from Agkistrodon acutus venom and its preliminary evaluation

A novel metalloproteinase, recombinant fibrinogenase IV (rFIVa), was expressed and purified from Agkistrodon acutus venom. It is a single-chain protein with an apparent molecular weight of 27 kDa. Western blot showed that it had a good immunological reaction against anti-FIVa rabbit serum. The kinetic parameters Km and Kcat of rFIVa on the substrate T6140 were 7.471×10−4 mol/l and 5.103×10−5 s−1. RFIVa cleaved preferentially the α-chain, and the β- and γ-chains of fibrinogen were also cleaved when the incubation time was prolonged. The administration of rFIVa (1.8  and 5.4 mg/kg) to animals with acute blood-stasis model produced a decrease in fibrinogen to control values. To our knowledge, this is the first report of the expression, purification, and evaluation of recombinant fibrinogenase IV, which belongs to class P-I metalloproteinase from A. acutus venom.