The plasminogen activator (PA) in snake venom, a serine protease, can convert plasminogen to active plasmin, indirectly causing the degradation of fibrin. It is difficult to purify sufficient snake venom PA (SV-PA) for clinical applications due to the low SV-PA content in venom. The gene encoding PA was obtained from the venom gland of Gloydius brevicaudus using RT-PCR with primers designed according to the N-terminal amino acids of G. brevicaudus venom PA (GBV-PA), was cloned into the prokaryotic expression vector pET-42a, and recombinant GBV-PA (rGBV-PA) was expressed via Isopropyl-beta-D-1-Thiogalactopyranoside (IPTG) induction. Like human tissue PA, the purified renatured rGBV-PA could significantly reduce the rabbit plasma euglobulin lysis time (ELT) and prevent thrombus formation in the inferior vena cava of rats. Within the dosage range, the dosage and effects were positively correlated. (C) 2013 Elsevier Inc. All rights reserved.