The present invention relates to the biotechnology field, more
particularly, to novel recombinant staphylokinase (RGD/KGD-Sak)
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 trimensional 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.