Gene clone and expression of a fibrinolytic enzyme (FE) in Escherichia coli

Abstract

Bacillus subtilis LD-8547, a strong fibrinolytic enzyme (FE) producing strain, was obtained by the mutation from Bacillus subtilis LD-8, isolated in our laboratory. Based on the homology, the DNA fragment encoding the intact FE was amplified from total DNA of Bacillus subtilis LD-8547 by PCR. The vector pET32a (+) was used to construct the N-terminal thioredoxin (Trx) fusion expression plasmid, and the recombinant FE was successfully expressed in Eschehchia coli BL21 (DE3). The expressed protein showed high fibrinolytic activity in soluble fraction. This study provided evidences that FE could be actively expressed in E. coli, and large quantities of FE could be produced for pharmacological and clinical research.