We cloned venom serine proteases from two bumblebee species, Bombus hypocrita sapporoensis and B. ardens ardens. We compared the predicted mature protein sequences of these serine proteasegenes to those previously reported from other bees. Using B. h. sapporoensis venom serine protease(Bs-VSP), we identify that Bs-VSP acts as a fibrin(ogen)olytic enzyme. Bs-VSP activates prothrombin and directly degrades fibrinogen into fibrin degradation products, as demonstrated for B. ignitus and B. terrestrisvenom serine proteases. Our results further define roles for bumblebee venom serine proteases as fibrin(ogen)olytic enzyme, providing strong evidence that bumblebee venom serine proteases are hemostatically active proteins that are potentially promising therapeutic agents.

• Yuling Qiu(College of Natural Resources and Life Science, Dong-A University)
• Hyung Joo Yoon(Department of Agricultural Biology, National Academy of Agricultural Science)
• Byung Rae Jin(College of Natural Resources and Life Science, Dong-A University)