Biochemical and Immunological Properties of Engineered Low-Immunogenic Staphylokinases for Next-Generation Thrombolytic Therapy

Strunga, A.; Peskova, M.; Krupka, M.; Zachova, K.; Sindlerova, L.; Neumeisterova, N.; Mican, J.; Vitecek, J.; Bednar, D.; Kubala, L.; Raska, M.; Damborsky, J.; Prokop, Z.

doi:10.64898/2026.01.04.697554

bioRxiv · 10.64898/2026.01.04.697554

Biochemical and Immunological Properties of Engineered Low-Immunogenic Staphylokinases for Next-Generation Thrombolytic Therapy

Strunga, A.·Peskova, M.·Krupka, M.·Zachova, K.·Sindlerova, L.·Neumeisterova, N.·Mican, J.·Vitecek, J.·Bednar, D.·Kubala, L.·Raska, M.·Damborsky, J.·Prokop, Z.

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Abstract

Staphylokinase (SAK) is a highly fibrin-specific plasminogen activator with significant potential as a safe and affordable thrombolytic. Yet, its clinical translation can be limited by potential immunogenicity. To accelerate the development of improved thrombolytics, a critical step is identifying the most suitable molecular template. Therefore, we performed a comparative analysis of biochemical and immunological properties of three engineered low-immunogenic variants (SAK SY155, SAK THR174, and SAK STAR FRIDA) and two wild-types (SAK STAR and SAK 42D), using a newly established panel of assays. All variants retained potent thrombolytic activity, with SAK SY155 displaying the highest catalytic efficiency and fibrin-clot permeability. However, this advantage did not fully translate into improved clot reduction under flow conditions. Comprehensive immunological profiling, including T lymphocyte proliferation, dendritic cell maturation, mouse immunization models, and human serum reactivity tests, confirmed decreased immunogenicity for two low-immunogenic variants. Overall, low-immunogenic SAK SY155 emerged as the most promising template for rational engineering of next-generation thrombolytics.

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Strunga, A., Peskova, M., Krupka, M., Zachova, K., Sindlerova, L., Neumeisterova, N., Mican, J., Vitecek, J., Bednar, D., Kubala, L., Raska, M., Damborsky, J., Prokop, Z.. 2026-01-04. Biochemical and Immunological Properties of Engineered Low-Immunogenic Staphylokinases for Next-Generation Thrombolytic Therapy. https://doi.org/10.64898/2026.01.04.697554

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