Mutations for decreasing the immunogenicity and maintaining the function of core streptavidin

Authors

  • Kyohei Yumura,

    1. Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan
    2. Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8562, Japan
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  • Mihoko Ui,

    1. Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8562, Japan
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  • Hirofumi Doi,

    1. Research Center for Advanced Science and Technology, The University of Tokyo, Komaba, Tokyo 153-8904, Japan
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  • Takao Hamakubo,

    1. Research Center for Advanced Science and Technology, The University of Tokyo, Komaba, Tokyo 153-8904, Japan
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  • Tatsuhiko Kodama,

    1. Research Center for Advanced Science and Technology, The University of Tokyo, Komaba, Tokyo 153-8904, Japan
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  • Kouhei Tsumoto,

    Corresponding author
    1. Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan
    2. Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8562, Japan
    • Institute of Medical Science, Transmittal form, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan
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  • Akira Sugiyama

    Corresponding author
    1. Research Center for Advanced Science and Technology, The University of Tokyo, Komaba, Tokyo 153-8904, Japan
    • Institute of Medical Science, Transmittal form, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan
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Abstract

The defining property of core streptavidin (cSA) is not only its high binding affinity for biotin but also its pronounced thermal and chemical stability. Although potential applications of these properties including therapeutic methods have prompted much biological research, the high immunogenicity of this bacterial protein is a key obstacle to its clinical use. To this end, we have successfully constructed hypoimmunogenic cSA muteins in a previous report. However, the effects of these mutations on the physicochemical properties of muteins were still unclear. These mutations retained the similar electrostatic charges to those of wild-type (WT) cSA, and functional moieties with similar hydrogen bond pattern. Herein, we performed isothermal titration calorimetry, differential scanning calorimetry, and sodium dodecyl sulfate–polyacrylamide gel electrophoresis to gain insight into the physicochemical properties and functions of these modified versions of cSA. The results indicated that the hypoimmunogenic muteins retained the biotin-binding function and the tetramer structure of WT cSA. In addition, we discuss the potential mechanisms underlying the success of these mutations in achieving both immune evasion and retention of function; these mechanisms might be incorporated into a new strategy for constructing hypoimmunogenic proteins.

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