Design of coiled-coil protein-origami cages that self-assemble in vitro and in vivo.

3 years ago

Design of coiled-coil protein-origami cages that self-assemble in vitro and in vivo.

Tanja Ćirković Veličković, Duško Lainšček, Jana Aupič, Ajasja Ljubetič, Iva Hafner-Bratkovič, José María Carazo, Mojca Benčina, Roberto Melero, Igor Drobnak, Fabio Lapenta, Andreja Majerle, Helena Gradišar, Roman Jerala, Tomaž Pisanski, Adam Round, Nuša Krivec, Žiga Strmšek

Polypeptides and polynucleotides are natural programmable biopolymers that can self-assemble into complex tertiary structures. We describe a system analogous to designed DNA nanostructures in which protein coiled-coil (CC) dimers serve as building blocks for modular de novo design of polyhedral protein cages that efficiently self-assemble in vitro and in vivo. We produced and characterized >20 single-chain protein cages in three shapes-tetrahedron, four-sided pyramid, and triangular prism-with the largest containing >700 amino-acid residues and measuring 11 nm in diameter. Their stability and folding kinetics were similar to those of natural proteins. Solution small-angle X-ray scattering (SAXS), electron microscopy (EM), and biophysical analysis confirmed agreement of the expressed structures with the designs. We also demonstrated self-assembly of a tetrahedral structure in bacteria, mammalian cells, and mice without evidence of inflammation. A semi-automated computational design platform and a toolbox of CC building modules are provided to enable the design of protein cages in any polyhedral shape.

Publisher URL: http://doi.org/10.1038/nbt.3994

DOI: 10.1038/nbt.3994