Codon Optimization, Cloning and Expression of Chimeric Streptokinase in E. coli

Abstract

Human’s haemostatic system fails to suppress undesirable blood clots due to insufficient activation of thrombolytic system, which leads to the obstruction of important arteries carrying oxygen and nutrients to imperative organs like brain and heart. Therefore, the obstruction of these important arteries may lead to pulmonary embolism, brain stroke and myocardial infarction. Streptokinase (EC 3.4.99.22) is a non-enzymatic, single chain, monomeric protein which comprises of 414 amino acid protein residues of 47 kDa. It is a non-fibrin specific drug which increases the risk of internal bleeding. Moreover, recombinant streptokinase protein expression is mostly found in the inclusion bodies. In current study efforts were made to make streptokinase fibrin-specific and achieve its soluble expression in E. coli. The results showed that by linking ompA signal sequence the soluble expression of chimeric fibrin specific streptokinase was achieved at 57 kDa. Through codon optimization, the expression of chimeric fibrin specific streptokinase has increased. The attachment of finger domain of tissue plasminogen activator with streptokinase has been a step forward in making streptokinase fibrin specific. This will help in minimizing the clinical limitations of streptokinase such as internal bleeding.