title: Supramolecular Nanotube of Chaperonin GroEL: Length Control for Cellular Uptake Using Single-Ring GroEL Mutant as End-Capper.
abstract: How to modulate supramolecular protein nanotubes without sacrificing their thermodynamic stability? This challenging issue emerged with an enhanced reality since our successful development of a protein nanotube of chaperonin GroELMC as a novel ATP-responsive 1D nanocarrier because the nanotube length may potentially affect the cellular uptake efficiency. Herein, we report a molecularly engineered protein end-capper (SRMC) that firmly binds to the nanotube termini since the end-capper originates from GroEL. According to the single-ring mutation of GroEL, we obtained a single-ring version of GroEL bearing cysteine mutations (GroELCys) and modified its 14 apical cysteine residues with merocyanine (MC). Whereas SRMC self-dimerizes upon treatment with Mg(2+), we confirmed that SRMC serves as the efficient end-capper for the Mg(2+)-mediated supramolecular polymerization of GroELMC and allows for modulating the average nanotube length over a wide range from 320 to 40 nm by increasing the feed molar ratio SRMC/GroELMC up to 5.4. We also found that the nanotubes shorter than 100 nm are efficiently taken up into HEP3B cells.
authors.affiliation: Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Seunghyun
authors.initials: S
authors.lastname: Sim
authors.affiliation: Research Unit for Cell Biology, Institute of Innovative Research, Tokyo Institute of Technology , Midori-ku, Yokohama 226-8501, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Niwa
authors.affiliation: Research Unit for Cell Biology, Institute of Innovative Research, Tokyo Institute of Technology , Midori-ku, Yokohama 226-8501, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Taguchi
authors.affiliation: Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.|RIKEN Center for Emergent Matter Science , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Takuzo
authors.initials: T
authors.lastname: Aida
mesh_terms: D002460:Cell Line; D018834:Chaperonin 60 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009154:Mutation; D043942:Nanotubes / Q000737:chemistry*; D015202:Protein Engineering; D017510:Protein Folding; D021381:Protein Transport
chemical_list: D018834:Chaperonin 60