Intrinsic hydrophobicity of IDP-based biomolecular condensates drives their partial drying on membrane surfaces

Journal article

The localization of biomolecular condensates to intracellular membrane surfaces has emerged as an important feature of sub-cellular organization. In this work, we study the wetting behavior of biomolecular condensates on various substrates. We use confocal microscopy to measure the contact angles of model condensates formed by intrinsically disordered protein Ddx4^N. We show the importance of taking optical aberrations into account, as these impact apparent contact angle measurements. Ddx4^N condensates are seen to partially dry (contact angles above 90°) a model membrane, with little dependence on the magnitude of charge on, or tyrosine content of, Ddx4^N. Further contact angle measurements on surfaces of varying hydrophilicity reveal a preference of Ddx4^N condensates for hydrophobic surfaces, suggesting an intrinsic repulsion between protein condensates and hydrophilic membrane surfaces. This observation is in line with previous studies relating protein adsorption to surface hydrophilicity. Our work advances the understanding of the molecular details governing the localization of biomolecular condensates.

Authors: Holland, J; Nott, TJ; Aarts, DGAL

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: AIP Publishing
• Journal: Journal of Chemical Physics
• Volume: 162
• Issue: 11
• Article number: 115101
• Publication date: 2025-03-17
• Acceptance date: 2025-02-19
• DOI: 10.1063/5.0253522
• EISSN: 1089-7690
• ISSN: 0021-9606
• Language: English