Physical Principles for Assemblies in Protein-complexes

Many proteins assemble into stable complexes or transient clusters to perform a biological function in the cytoplasm. Unlike stable complexes that can be visualized with super-resolution microscopy, the detection of transient clusters is elusive as the composition of protein assemblies vary with cellular conditions. A main challenge is to establish the physical principles that govern assembly that takes the transient nature into account. Here, we utilized the tools of statistical inference and modeling from experimental data dealing with the average abundances of various protein species. Resulting from our model, the grand canonical Monte Carlo simulations of multi-component protein-complex mixture accurately reproduce transient complex formation found by experiments. We also provide general insight into the physical principles that govern these complex assemblies.