Posted on August 27, 2017

I have a new paper on the arXiv that takes a somewhat different perspective on the problem of capsid assembly. The system we are studying in this paper is not a capsid per say, but rather the carboxysome. Carboxysomes are organelle-like structures found in photosynthetic bacteria. Biologically, they play an important role in carbon sequestration because they concentrate an enzyme called RuBisCO, which helps convert carbon dioxide to sugars. Together with Phill Geissler, I built a model to study the dynamics of carboxysome that incorporates a minimal set of physical assumptions.

Perhaps surprisingly, a simple analysis demonstrates that the equilibrium state of our model is a macroscopically large shell coating a macroscopically large condensed globule of “cargo.” However, in biological systems, it has been observed that the carboxysome has a narrow distribution of sizes (with a radius on the nano—not marcro—scale). Our paper demonstrates that a tight size distribution can emerge as the result of a nonequilibrium dynamics. In addition, we give clear, easily experimentally tunable control parameters that help determine the size distribution.

You can find the details on the [arXiv].