Molecularly Engineered “Janus GroEL”: Application to Supramolecular Copolymerization with a Higher Level of Sequence Control

• Published in: Journal of the American Chemical Society Vol. 142; no. 31; pp. 13310 - 13315
• Main Authors: Kashiwagi, Daiki, Shen, Hao K, Sim, Seunghyun, Sano, Koki, Ishida, Yasuhiro, Kimura, Ayumi, Niwa, Tatsuya, Taguchi, Hideki, Aida, Takuzo
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 05.08.2020
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.0c05937

Herein we report the synthesis and isolation of a shape-persistent Janus protein nanoparticle derived from the biomolecular machine chaperonin GroEL ( A GroEL B ) and its application to DNA-mediated ternary supramolecular copolymerization. To synthesize A GroEL B with two different DNA strands A and B at its opposite apical domains, we utilized the unique biological property of GroEL, i.e., Mg2+/ATP-mediated ring exchange between A GroEL A and B GroEL B with their hollow cylindrical double-decker architectures. This exchange event was reported more than 24 years ago but has never been utilized for molecular engineering of GroEL. We leveraged DNA nanotechnology to purely isolate Janus A GroEL B and succeeded in its precision ternary supramolecular copolymerization with two DNA comonomers, A** and B*, that are partially complementary to A and B in A GroEL B , respectively, and programmed to self-dimerize on the other side. Transmission electron microscopy allowed us to confirm the formation of the expected dual-periodic copolymer sequence −( B*/B GroEL A/A**/A**/A GroEL B/B* )– in the form of a laterally connected lamellar assembly rather than a single-chain copolymer.