Cloning and Expression of Streptokinase Gene from Streptococcus pyogenes C1

In recent years more people die each year from cardiovascular diseases (CVDs) than from any other cause and 17.7 million people died from CVDs in 2015, representing about one third of all global deaths ac¬cording to the WHO. Streptokinase is a thrombolytic agent with systemic fibrinolytic effect. It is a non-en¬zymatic protein produced by β haemolytic streptococci and activates the fibrinolytic system indirectly. Streptokinase is used widely and routinely for treatment of acute myocardial infarctions. In this study strep¬tokinase gene from Streptococcus pyogenes C1 was cloned in pET28a vector and transferred to Escherichia coli BL21. Expressed protein was purified by Ni-NTA column and visualized with SDS-PAGE. Streptoki¬nase (SK) coding DNA fragment was amplified from S. pyogenes C1 genomic DNA by PCR. The amplifi¬cation products were inserted into the cloning and expression vector pET28a(+). Recombinant pET28a(+) plasmid with recSK gene were then introduced to E. coli BL21 (DE3) by electroporation. The streptokinase encoded by the plasmid pET28a(+) contains the mature streptokinase with the 6X histidine-tag.