Non-Covalently Associated Streptavidin Multi-Arm Nanohubs Exhibit Mechanical and Thermal Stability in Cross-Linked Protein-Network Materials

David S. Knoff, Samuel Kim, Kareen A. Fajardo Cortes, Jocelyne Rivera, Marcus V.J. Cathey, Dallas Altamirano, Christopher Camp, Minkyu Kim

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Constructing protein-network materials that exhibit physicochemical and mechanical properties of individual protein constituents requires molecular cross-linkers with specificity and stability. A well-known example involves specific chemical fusion of a four-arm polyethylene glycol (tetra-PEG) to desired proteins with secondary cross-linkers. However, it is necessary to investigate tetra-PEG-like biomolecular cross-linkers that are genetically fused to the proteins, simplifying synthesis by removing additional conjugation and purification steps. Non-covalently, self-associating, streptavidin homotetramer is a viable, biomolecular alternative to tetra-PEG. Here, a multi-arm streptavidin design is characterized as a protein-network material platform using various secondary, biomolecular cross-linkers, such as high-affinity physical (i.e., non-covalent), transient physical, spontaneous chemical (i.e., covalent), or stimuli-induced chemical cross-linkers. Stimuli-induced, chemical cross-linkers fused to multi-arm streptavidin nanohubs provide sufficient diffusion prior to initiating permanent covalent bonds, allowing proper characterization of streptavidin nanohubs. Surprisingly, non-covalently associated streptavidin nanohubs exhibit extreme stability, which translates into material properties that resemble hydrogels formed by chemical bonds even at high temperatures. Therefore, this study not only establishes that the streptavidin nanohub is an ideal multi-arm biopolymer precursor but also provides valuable guidance for designing self-assembling nanostructured molecular networks that can properly harness the extraordinary properties of protein-based building blocks.

Original languageEnglish (US)
Pages (from-to)4130-4140
Number of pages11
Issue number10
StatePublished - Oct 10 2022

ASJC Scopus subject areas

  • Bioengineering
  • Biomaterials
  • Polymers and Plastics
  • Materials Chemistry

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