Construction of translation-coupled bicistronic expression vector and soluble expression of lumbrokinase F238 in E. coli

Abstract:

In order to express soluble foreign proteins in E. coli, a bicistronic translation-coupled expression vector pDICT was constructed by using thioredoxin as a molecular chaperone. In this study, the expression vector pDICT was built by inserting thioredoxin gene into the pET22b vector between Nde I and EcoR I sites, and adding ribosome binding site before the stop codon of thioredoxin. Lumbrokinase gene F238 was cloned into this vector, and transformed into E. coli BL21(DE3), then the recombinant protein was induced by IPTG. SDS-PAGE results showed that the Lumbrokinase F238 was soluble expressed. The fibrinolytic activity was measured by using artificial fibrin plates, and the result indicated that Lumbrokinase could directly dissolve fibrous protein, and also had fibrinokinase activity which could indirectly dissolve fibrous protein. Construction of the bicistronic translation-coupled expression vector provides a new method to achieve soluble expression of heterologous proteins in E. coli.