RESUMEN
A recombinant RGD-Staphylokinase(RGD-Sak) with thrombolytic and anti-thrombolytic bifunction was expressed in E. coli. The expression product accumulates as inclusion bodies. In order to obtain active molecule, the RGD-Sak in the inclusion body should be denatured and then renatured. The renaturation of RGD-Sak was performed by gel filtration. Comparing with the traditional way of dilution renaturation, gel filtration way is better than the traditional one, since there are some advantages, such as simple processing, high recovery, low cost and higher purity after renaturation, After renaturation, RGD-Sak was purified by Q-Sepharose FF, and the purity was more than 95%. Analysis of CD spectra showed that the final product from the two renaturation ways have similar CD spectra. It was demonstrated that RGD-Sak molecules proceeded correct refolding through gel filtration or dilution renaturation process.