the present invention relates to the biotechnology field , more particularly , to novel recombinant staphylokinase derivatives and the preparation the thereof . the derivatives , have a low polymerizing ability , low immunogenicity and a bifunctionality of thrombolytics and anticoagulant . based on the line , structural analysis of the monomer and dimer of recombinant staphylokinases and their biochemical properties , we designed two novel bifunctional staphylokinase molecular structures . mutant genes were constructed by pcr site - directed mutagenesis which were then recombined with a prokaryotic vector and used to transform e . coli . engineered strains with a high expression level were selected by screening and propagated by fermentation , followed by disruption of the cells , centrifugation to collect inclusion bodies , renaturation , and purification of rgd / kgd - sak through a two - step method . after lyophilized , the polymerizing ability and immunogenicity of the products decreased significantly . the derivatives can not only activate fibrinogen to lyse thrombus , but also significantly inhibit the platelet aggregation induced by adp , suggesting that they have the bifunctionality of thrombolytics and anticoagulant .