Send to

Choose Destination
Proc Natl Acad Sci U S A. 2017 Aug 22;114(34):9014-9019. doi: 10.1073/pnas.1706825114. Epub 2017 Aug 8.

Beyond icosahedral symmetry in packings of proteins in spherical shells.

Author information

School of Mathematics, University of Bristol, Bristol BS8 1TW, United Kingdom;
BrisSynBio, Life Sciences Building, Bristol BS8 1TQ, United Kingdom.
School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom.
School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom.
BrisSynBio, Life Sciences Building, Bristol BS8 1TQ, United Kingdom;


The formation of quasi-spherical cages from protein building blocks is a remarkable self-assembly process in many natural systems, where a small number of elementary building blocks are assembled to build a highly symmetric icosahedral cage. In turn, this has inspired synthetic biologists to design de novo protein cages. We use simple models, on multiple scales, to investigate the self-assembly of a spherical cage, focusing on the regularity of the packing of protein-like objects on the surface. Using building blocks, which are able to pack with icosahedral symmetry, we examine how stable these highly symmetric structures are to perturbations that may arise from the interplay between flexibility of the interacting blocks and entropic effects. We find that, in the presence of those perturbations, icosahedral packing is not the most stable arrangement for a wide range of parameters; rather disordered structures are found to be the most stable. Our results suggest that (i) many designed, or even natural, protein cages may not be regular in the presence of those perturbations and (ii) optimizing those flexibilities can be a possible design strategy to obtain regular synthetic cages with full control over their surface properties.


coarse-grained modeling; icosahedral symmetry; protein cage; protein design; self-assembly

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center