Hierarchical assembly is more robust than egalitarian assembly in synthetic capsids

Abstract

Self-assembly of complex and functional materials remains a grand challenge in soft material science. Efficient assembly depends on a delicate balance between thermodynamic and kinetic effects, requiring fine-tuning affinities and concentrations of subunits. By contrast, we introduce an assembly paradigm that allows large error-tolerance in the subunit affinity and helps avoid kinetic traps. Our combined experimental and computational approach uses a model system of triangular subunits programmed to assemble into T=3 icosahedral capsids comprising 60 units. The experimental platform uses DNA origami to create monodisperse colloids whose 3D geometry is controlled to nanometer precision, with two distinct bonds whose affinities are controlled to kBT precision, quantified in situ by static light scattering. The computational model uses a coarse-grained representation of subunits, short-ranged potentials, and Langevin dynamics. Experimental observations and modeling reveal that when the bond affinities are unequal, two distinct hierarchical assembly pathways occur, in which the subunits first form dimers in one case, and pentamers in another. These hierarchical pathways produce complete capsids faster and are more robust against affinity variation than egalitarian pathways, in which all binding sites have equal strengths. This finding suggests that hierarchical assembly may be a general engineering principle for optimizing self-assembly of complex target structures.

References in corpus (8)

• Mechanisms of virus assembly
• The self-assembly and evolution of homomeric protein complexes
• Controlling Viral Capsid Assembly with Templating
• Geometrically programmed self-limited assembly of tubules using DNA origami colloids
• Designing the self-assembly of arbitrary shapes using minimal complexity building blocks
• Design strategies for the self-assembly of polyhedral shells
• Tiling a tubule: How increasing complexity improves the yield of self-limited assembly
• Exact Solution for Elastic Networks on Curved Surfaces

Cited by in corpus (4)

• Assembly of Complex Colloidal Systems Using DNA
• The polyhedral structure underlying programmable self-assembly
• Active assembly and non-reciprocal dynamics of elastic membranes
• Experimental demonstration of kinetic proofreading inherited in ligation-based information replication