Expression and Characterization of Earthworm Eisenia foetida Lumbrokinase‐3 in Pichia pastoris

Abstract Lumbrokinase‐3 (LK‐3, AY438622), first cloned from the earthworm Eisenia foetida in our laboratory, is a component of earthworm fibrinolytic enzymes. In this study, cDNA encoding the LK‐3 gene was sub‐cloned into yeast pPIC9K expression vector and transformed into the Pichia pastoris GS115 cells by electroporation. High level expression of LK‐3 in yeast cells was confirmed with a different induction time. The activity of expressed LK‐3 was observed in fibrin plates. In addition, the expressed LK‐3 protein could dissolve fibrinogen and bovine serum albumin. The use of this system for the high level production of biological protein is implicated from this study.