Production and purification of recombinant streptokinase using pMAL expression vector

Abstract

Background: Streptokinase (SK) is an effective and specific thrombolytic treatment of acute myocardial infarction. Despite its significant limitations, streptokinase remains the drug of choice particularly in countries with poorer economies because of its relatively low cost. In this study, the production and purification of streptokinase using a pMAL expression vector were evaluated. Methods: The pMAL vector, including the skc gene, obtained from Streptococcus equisimilis H46A, was transformed into E. coli BL21 to produce the soluble active fusion protein SK-MBP. The conditions of SK production were optimized by manipulating temperature, induction time and IPTG concentrations. This protein was purified by DEAE-sepharose column chromatography and the final purity was determined and activity of purified SK-MBP was measured using a synthetic substrate (S2251). Results: After optimizing the production conditions, SK-MBP was the major portion of total protein. Purified SK-MBP formed a single band using SDS-PAGE and had high biological activity. Conclusion: In this study we used pMAL expression vector to produce SK-MBP in E. coli BL21. Using this method we prevented the accumulation of inclusion bodies in spite of the high level of production of SK-MBP. Choosing a suitable host organism for the production of recombinant proteins is one of the most important factors that influence the level of desired protein production. Further studies are recommended to test other host organisms for this purpose.

Keywords

• Thrombolytic
• pMAL