(672g) Liquid-Liquid Phase Separation of Intrinsically Disordered Peptides (Invited Speaker)

Intrinsically disordered peptides (IDP) are a special class of proteins that do not fold to a unique three-dimensional shape. These proteins play important roles in the cell, from signaling to serving as structural scaffolds. Under pathological conditions, they can self-assemble into structures that are toxic to the cell, and a number of neurodegenerative diseases are associated with the self-assembly of IDPs into fibrillar structures. In addition to forming fibrils, many IDP can also phase separate into a protein rich and a protein depleted phase, a process known as liquid-liquid phase separation (LLPS). The cellular role of LLPS is not fully understood, and it has been suggested that the LLPS process may play a protective role in the cell against pathological fibrillization. I will present molecular dynamics and field theoretic simulations to map out the phase diagram of IDPs (with an emphasis on the Tau protein implicated in Alzheimer’s Disease), and compare and contrast the phase separation of biological polymers and synthetic polymers.