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Updated: Oct 25, 2026

Lipid-Protein Membrane Structure-Function Characterization using Droplet Interface Bilayers
Published on: June 12, 2026
Lipid Composition Modulates Secondary Structure at the Biocondensate-Membrane Interface
1Department of Chemistry, University of Texas at Austin, Austin, Texas78712, United States.
Abstract:
Biomolecular condensates (BMCs) formed through liquid-liquid phase separation (LLPS) play key roles in cellular organization, yet their molecular-scale interactions with membranes remain poorly understood. Here, we use surface-enhanced infrared absorption spectroscopy (SEIRAS) to quantify the secondary structure of poly-GR (glycine-arginine) inside condensates in contact with supported lipid bilayers. Amide I SEIRAS provides a surface-sensitive measure of the peptide backbone conformation at the membrane-condensate interface. Results show that neutral POPC bilayers preserve the β-sheet rich organization of the bulk condensate, whereas negatively charged POPC/POPS bilayers reduce β-sheet content and enhance β-turn formation, accompanied by perturbations of the lipid headgroups. These results demonstrate that membrane charge modulates condensate secondary structure, hydration, and interfacial behavior, providing molecular-level insight into electrostatic regulation of condensate organization at the membrane-water interface.
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