【Soft Matter Lecture148】Liquid-liquid phase separation mediated self-assembly of bioinspired peptides and proteins



Liquid-liquid phase separation (LLPS) emerges as a powerful strategy for orchestrating the assembly of peptides and proteins with precision. A prime illustration of this is found in our investigation into mussel-inspired wet adhesives. Marine mussels exhibit remarkable underwater adhesion capabilities, attributed to the secretion of mussel foot proteins (Mfps) that undergo coacervation or LLPS. Despite their effectiveness, the molecular underpinnings of Mfps' phase separation remain elusive. Our findings reveal that a peptide, GK-16*, modeled after the primary adhesive protein Mfp-5, readily forms coacervates under marine conditions. Through molecular dynamics simulations and targeted point mutation studies, we identified that the hydrogen-bonding interactions facilitated by Dopa and Gly residues are crucial for coacervation. Interestingly, we can modulate the characteristics of GK-16* coacervates by adjusting the solution's pH and salt concentration, thereby altering the electrostatic and hydrogen-bonding dynamics. Our second example delves into a self-assembly system inspired by insect cuticular proteins (ICPs). In a mixed solvent of water and acetone, these peptides can self-assemble into hollow nano-capsules driven by LLPS. Biochemical analyses indicate a transition of ICPs into a beta-sheet configuration during assembly, a critical step for the formation of nano-capsules.




Jing Yu is an Associate Professor in the School of Materials Science and Engineering at Nanyang Technological University (NTU), Singapore. He earned his Ph.D. in Chemical Engineering in 2012 from the University of California, Santa Barbara with Prof Jacob Israelachvili, followed by a postdoc at Caltech and a postdoc at the University of Chicago. In 2017, he became an Assistant Professor at NTU. His research interests lie in the characterization of dynamic properties of biological and bio-inspired materials with hierarchical structures. He aspires to gain molecular-level control of soft materials, enabling him to design integrated, multifunctional materials and interfaces.