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Cloning and expression of a new recombinant thrombolytic and anthithrombotic agent - a staphylokinase variant

Department of Medical Biochemistry, Medical University of Lodz, Łódź, Poland.
Acta biochimica Polonica (Impact Factor: 1.15). 12/2008; 56(1):41-53.
Source: PubMed


To develop a more potent antithrombin agent with thrombolytic and antiplatelet properties, a new staphylokinase (SAK) variant was constructed. The kringle 2 domain (K2) of tissue type-plasminogen activator (t-PA) containing a fibrin-specific binding site (i), the RGD sequence (Arg-Gly-Asp) for the prevention of platelet aggregation (ii) and the antithrombotic agent - hirulog (iii) was assembled to the C-terminal part of recombinant staphylokinase (r-SAK). cDNA for the hybrid protein SAK-RGD-K2-Hirul was cloned into Pichia pastoris pPIC9K yeast expression vector. The introduction of K2 t-PA, the RGD sequence and hirulog into the C-terminus of r-SAK did not alter the staphylokinase activity. We observed a higher clot lysis potency of SAK-RGD-K2-Hirul as evidenced by a faster and more profound lysis of (125)I-labeled human fibrin clots. The potency of thrombin inhibition by the hirulog C-terminal part of the recombinant fusion protein was almost identical to that of r-Hir alone. These results suggest that the SAK-RGD-K2-Hirul construct can be a more potent and faster-acting thrombolytic agent with better antithrombin and antiplatelet properties compared to r-SAK and SAK-RGD-K2-Hir.

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    • "Various SAK-based multifunctional recombinant proteins were constructed and expressed in different expression system in earlier studies to reduce the reocclusion and bleeding complications. Fusion proteins SAK-RGD-K2-Hir and SAK-RGD-K2-Hirul were constructed and produced in different eukaryotic expression host, Schizosaccharomyces pombe [17] and Pichia pastoris [18], respectively. Furthermore, a SAK variant (SAK-HV) with 12 amino acids thrombinbinding domain from hirudin was also constructed and expressed in E. coli BL21 (DE3) [19]. "
    [Show abstract] [Hide abstract] ABSTRACT: The thrombolytic therapy with clinically approved drugs often ensues with recurrent thrombosis caused by thrombin-induced platelet aggregation from the clot debris. In order to minimize these problems, a staphylokinase (SAK)-based bacterial friendly multifunctional recombinant protein SRH (staphylokinase (SAK) linked with tripeptide RGD and dodecapeptide Hirulog (SRH)) was constructed to have Hirulog as an antithrombin agent and RGD (Arg-Gly-Asp) as an antiplatelet agent in the present study. This multifunctional fusion protein SRH was expressed in osmotically inducible E. coli GJ1158 as soluble form and purified with a yield of 0.27 g/L and functionally characterized in vitro. SRH retained the fibrinolytic activity and plasminogen activation rate comparable to the parental counterpart SAK. The antithrombin activity of SRH was significantly higher than SAK. The platelet rich clot lysis assay indicated that SRH had enhanced platelet binding activity and T 50% and C50 of SRH were significantly lower than that of SAK. Furthermore, SRH inhibited the ADP-induced platelet aggregation in dose-dependent manner while SAK had no significant effect on platelet aggregation. Thus, the current study suggests that the SAK variant produced from osmotically inducible GJ1158 is more potent thrombolytic agent with antithrombin and antiplatelet aggregation activities for reduction of reocclusion in thrombolytic therapy.
    Full-text · Article · Aug 2013 · BioMed Research International
  • No preview · Article · Feb 2010 · Journal of Medicinal Chemistry
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    [Show abstract] [Hide abstract] ABSTRACT: SAK-RGD-K2-Hir and SAK-RGD-K2-Hirul are recombinant proteins that are derivatives of r-SAK (recombinant staphylokinase). They are characterized by their fibrin-specific plasminogen activation properties and their antithrombin and antiplatelet activities. The difference between these proteins is the presence of the antithrombotic fragment (hirudin or hirulog) in the C-terminal portion of the r-SAK. The aim of the present study was to examine the thrombolytic potentials of SAK-RGD-K2-Hir and SAK-RGD-K2-Hirul in an electrically induced carotid artery thrombosis model in rats and to compare the potentials to that of r-SAK. We determined that a bolus injection of SAK-RGD-K2-Hirul was more effective than one of r-SAK in the improvement and maintenance of carotid patency and in arterial thrombus weight reduction; however, it had the same potency as SAK-RGD-K2-Hir. The bleeding time, prothrombin time and activated partial thromboplastin time were significantly prolonged in the animals that were treated with either dose (1.5 or 3.0 mg/kg) of SAK-RGD-K2-Hir or SAK-RGD-K2-Hirul, whereas no changes were observed in the plasma fibrinogen concentration or the α2 plasmin inhibitor level. r-SAK alone did not change the bleeding time or coagulation parameters. In conclusion, our findings demonstrate the thrombolytic activity of intravenous bolus injection of the novel thrombolytic agent SAK-RGD-K2-Hirul in rats. Although this protein compares favorably with r-SAK, we were unable to show the presence of any beneficial effects of SAK-RGD-K2-Hirul over those of SAK-RGD-K2-Hir. Furthermore, our results suggest that high doses of SAK-RGD-K2-Hirul bear the risk of bleeding.
    Full-text · Article · Sep 2011 · Pharmacological reports: PR
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