Dynamics of intrinsically disordered proteins and their droplet-like aggregates

The  intrinsically disordered proteins (IDPs) may aggregate and form multiprotein droplets that act as membraneless organelles. Theoretical understanding of the formation and dynamics of such droplets requires using coarse-grained molecular dynamics models. We describe a novel model (constructed with Lukasz Mioduszewski) that is a generalization of the so-called Go-like model, originally designed for structured proteins, and based on the concept of contact interactions between amino acids. In the case of the IDPs, the contacts are derived primarily from an instantaneous shape of the backbone and not from the geometry of a single reference state (such as the native state). The metastable proteinaceous droplets may arise within the two-fluid coexistence region that is bounded by the binodal and spinodal lines. We present novel theoretical methods to derive these lines. As an illustration, we discuss phase diagrams for systems of elastins and polyglutamines.