Disulfide-mediated conversion of 8-mer bowl-like protein architecture into three different nanocages

Abstract

Constructing different protein nanostructures with high-order discrete architectures by using one single building block remains a challenge. Here, we present a simple, effective disulfide-mediated approach to prepare a set of protein nanocages with different geometries from single building block. By genetically deleting an inherent intra-subunit disulfide bond, we can render the conversion of an 8-mer bowl-like protein architecture (NF-8) into a 24-mer ferritin-like nanocage in solution, while selective insertion of an inter-subunit disulfide bond into NF-8 triggers its conversion into a 16-mer lenticular nanocage. Deletion of the same intra-subunit disulfide bond and insertion of the inter-subunit disulfide bond results in the conversion of NF-8 into a 48-mer protein nanocage in solution. Thus, in the laboratory, simple mutation of one protein building block can generate three different protein nanocages in a manner that is highly reminiscent of natural pentamer building block originating from viral capsids that self-assemble into protein assemblies with different symmetries.

Artificial Organelles: Towards Adding or Restoring Intracellular Activity

“…Especially the plethora of design features that can be included is very promising. For example, protein cages can be designed in a scalable [242] or adaptable [243] manner by incorporating split inteins or disulfide interactions, respectively. Alternatively, capsid assembly can be controlled allosterically [244] or via chemical, thermal and redox control over metal coordination [245] .…”

Ferritin Nanocage: A Versatile Nanocarrier Utilized in the Field of Food, Nutrition, and Medicine

“…The pseudo - D 2 interface consists of the C-terminal end of helix A, the N-terminal end of helix B, as well as N-terminal end of helix C. In the crystal structure, there is a large “window” (four in the whole molecule) in the perpendicular directions of the 16-mer nanocage, with an aperture of about 65 nm, which actually obscured by disordered C-terminal tails of two monomers [ 48 , 49 ]. Subsequently, using the above-mentioned 8-mer non-native protein as the building block, a set of discrete protein nanocages with different sizes and geometries (24-mer, 16-mer, and 48-mer) was constructed through deletion of one inherent intra-subunit S–S bond formed within one subunit, insertion of inter-subunit S–S bonds at the protein interface, and deletion of the intra-subunit S–S bonds along with insertion of the inter-subunit S–S bonds, respectively ( Figure 3 B) [ 50 ].…”

“…, 2016, respectively.). ( B ) Schematic representation of the conversions from 8-mer bowl-like proteins to protein nanocages with different sizes and geometries (24-mer, 16-mer, and 48-mer) (Reproduced with permission from [ 50 ], Nat. Commun., 2019).…”

Connectability of protein cages

“…2IV). 26 Circular permutation, a modality to alter the connectivity of secondary structure elements in a protein, 27 has also been employed to modulate the assembly states of shell proteins derived from the propanediol utilization (Pdu) compartment and lumazine synthase. 28,29 In the former protein's case, the tile-forming hexameric subunit was converted to a pentamer that self-assembles into a dodecahedral cage, 28 while the latter forms expanded spherical cages, compared to the wild type assembly, as well as tubular structures with morphologies dependent on the length of the peptide linker connecting the native termini ( Fig.…”