Dynamic frustrated charge hotspots created by charge density modulation sequester globular proteins into complex coacervates

IR (HANDLE) Open Access
  • K C, Biplab
    Graduate School of Systems Life Sciences, Kyushu University
  • Nii, Teruki
    Department of Applied Chemistry, Faculty of Engineering, Kyushu University
  • Mori, Takeshi
    Department of Applied Chemistry, Faculty of Engineering, Kyushu University Center for Future Chemistry, Kyushu University
  • Katayama, Yoshiki
    Department of Applied Chemistry, Faculty of Engineering, Kyushu University Center for Future Chemistry, Kyushu University Center for Molecular Systems, Kyushu University
  • Kishimura, Akihiro
    Department of Applied Chemistry, Faculty of Engineering, Kyushu University Center for Future Chemistry, Kyushu University Center for Molecular Systems, Kyushu University

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Description

This study presents a simple strategy for the sequestration of globular proteins as clients into synthetic polypeptide-based complex coacervates as a scaffold, thereby recapitulating the scaffold-client interaction found in biological condensates. Considering the low net charges of scaffold proteins participating in biological condensates, the linear charge density (σ) on the polyanion, polyethylene glycol-b-poly(aspartic acids), was reduced by introducing hydroxypropyl or butyl moieties as a charge-neutral pendant group. Complex coacervate prepared from the series of reduced-σ polyanions and the polycation, homo-poly-L-lysine, could act as a scaffold that sequestered various globular proteins with high encapsulation efficiency (>80%), which sometimes involved further agglomerations in the coacervates. The sequestration of proteins was basically driven by electrostatic interaction, and therefore depended on the ionic strength and charges of the proteins. However, based on the results of polymer partitioning in the coacervate in the presence or absence of proteins, charge ratios between cationic and anionic polymers were maintained at the charge ratio of unity. Therefore, the origin of the electrostatic interaction with proteins is considered to be dynamic frustrated charges in the complex coacervates created by non-neutralized charges on polymer chains. Furthermore, fluorescence recovery after photobleaching (FRAP) measurements showed that the interaction of side-chains and proteins changed the dynamic property of coacervates. It also suggested that the physical properties of the condensate are tunable before and after the sequestration of globular proteins. The present rational design approach of the scaffold-client interaction is helpful for basic life-science research and the applied frontier of artificial organelles.

Journal

  • Chemical Science

    Chemical Science 14 (24), 6608-6620, 2023-05-19

    Royal Society of Chemistry (RSC)

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Details 詳細情報について

  • CRID
    1050018428980201216
  • NII Book ID
    AA12555653
  • ISSN
    20416539
    20416520
  • HANDLE
    2324/7173543
  • Text Lang
    en
  • Article Type
    journal article
  • Data Source
    • IRDB

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