Collective deformation modes promote fibrous self-assembly in protein-like particles
Mert Terzi (LPTMS)
Online seminar — ZOOM Meeting ID: 996 6280 8820 — Password: ask L. Mazza and D. Petrov —
Self-assembly is a crucial and ubiquitous process for biological systems, in which the building blocks spontaneously organize into larger complexes. If the building blocks fit each other, self-assembly leads to space filling aggregates. However, in the case of misfitting particles, the resulting aggregates may have limiting sizes. When the misfitting particles are deformable, elastic energy builds up during the assembly. The energy cost of elastic deformation competes with a surface tension which drives the particles into assembly. In the regime in which these two energies are comparable, particles can assemble into self-limiting structures. The relationship between characteristics of the individual particles and the resulting aggregates is not well understood. Through numerical simulations and elastic coarse-graining we show that this relationship is dominated by collective aggregate deformation modes in a broad class of soft particles. We identify two characteristics of particles predictive of the overall aggregate structure. When individual particles have soft deformation modes, these modes collectively control the size of self-limiting aggregates and lead to large-scale structures. The second characteristics is incompressibility which favors anisotropic, and hence fibrous aggregates. Finally, we discuss the implications of our results to fiber formation in protein aggregation.