Self-assembly of temperature-responsive protein-polymer bioconjugates

Dafni Moatsou, Jian Li, Arnaz Ranji, Anais Pitto-Barry, Ioanna Ntai, Michael C. Jewett, Rachel K. O'Reilly

Research output: Contribution to journalArticlepeer-review

54 Citations (Scopus)
101 Downloads (Pure)


We report a simple temperature-responsive bioconjugate system comprising superfolder green fluorescent protein (sfGFP) decorated with poly[(oligo ethylene glycol) methyl ether methacrylate] (PEGMA) polymers. We used amber suppression to site-specifically incorporate the non-canonical azide-functional amino acid p-azidophenylalanine (pAzF) into sfGFP at different positions. The azide moiety on modified sfGFP was then coupled using copper-catalyzed “click” chemistry with the alkyne terminus of a PEGMA synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization. The protein in the resulting bioconjugate was found to remain functionally active (i.e., fluorescent) after conjugation. Turbidity measurements revealed that the point of attachment of the polymer onto the protein scaffold has an impact on the thermoresponsive behavior of the resultant bioconjugate. Furthermore, small-angle X-ray scattering analysis showed the wrapping of the polymer around the protein in a temperature-dependent fashion. Our work demonstrates that standard genetic manipulation combined with an expanded genetic code provides an easy way to construct functional hybrid biomaterials where the location of the conjugation site on the protein plays an important role in determining material properties. We anticipate that our approach could be generalized for the synthesis of complex functional materials with precisely defined domain orientation, connectivity, and composition.
Original languageEnglish
Pages (from-to)1890-1899
Number of pages10
JournalBioconjugate Chemistry
Issue number9
Early online date17 Jun 2015
Publication statusPublished - 16 Sept 2015


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