Tuning materials properties of globular protein-based condensates

Abstract

AbstractThe phase separation of biomolecules into biomolecular condensates has emerged as a ubiquitous cellular process. Understanding how intrinsically disordered protein sequence controls condensate formation and material properties has led to the development of functional synthetic condensates. However, it is also crucial to understand the impact of folded domains on condensate properties. We set out to determine how distribution of sticker interactions across a globular protein contributes to network properties of hybrid protein-polymer condensates and to what extent globular protein-polyelectrolyte coacervates differ from those formed from two linear components. We designed three variants of green fluorescent protein with different charge patterning and used dynamic light scattering microrheology to measure the viscoelastic spectrum over a timescale of 10-6to 10 seconds, elucidating the response of protein condensates in this range for the first time. We further showed that the phase behavior and rheological characteristics of the condensates varied as a function of both protein charge distribution and polymer/protein ratio. Together, this work provides an increase in fundamental understanding of complex dynamic materials across length-scales.