Decoding the physical principles of two-component biomolecular phase separation

• DOI: 10.7554/elife.62403
• Publication Date: 2021-03-11T16:00:22Z
• Authors: Yaojun Zhang; Bin Xu; Benjamin G Weiner; Yigal Meir; Ned S Wingreen
• Keywords: Stoichiometry; Component (thermodynamics)

Cells possess a multiplicity of non-membrane-bound compartments, which form via liquid-liquid phase separation. These condensates assemble and dissolve as needed to enable central cellular functions. One important class is those composed two associating polymer species that one-to-one specific bonds. What are the physical principles underlie separation in such systems? To address this question, we employed coarse-grained molecular dynamics simulations examine how boundaries depend on valence, stoichiometry, binding strength. We discovered striking phenomenon – for sufficiently strong binding, suppressed at rational stoichiometries, termed magic-ratio effect. further developed an analytical dimer-gel theory confirmed effect disentangled individual roles properties shaping diagram. Our work provides new insights into factors controlling diagrams biomolecular condensates, with implications natural synthetic systems.