Biomolecular condensates modulate membrane lipid packing and hydration

Area of Science:

• Cell Biology
• Biophysics
• Biochemistry

Background:

• Membrane wetting by biomolecular condensates is crucial for cellular functions but lacks mechanistic understanding.
• The molecular basis of condensate formation and their interaction with lipid membranes remains largely unknown.

Purpose of the Study:

• To investigate the molecular mechanisms of biomolecular condensate formation and membrane wetting.
• To explore the relationship between condensate properties and lipid membrane packing.

Main Methods:

• Utilized ACDAN and LAURDAN dyes as nano-environmental sensors.
• Employed phasor analysis with hyperspectral and lifetime imaging microscopy.
• Used glycinin condensates and giant vesicles as model systems.

Main Results:

• Glycinin condensates showed altered water dynamics with changing salinity due to protein structural changes.
• Increased wetting affinity correlated with enhanced lipid packing in membranes interacting with protein and polymer condensates.
• Observed decreased water dipolar relaxation, indicating a general condensate wetting effect on membrane packing.

Conclusions:

• Biomolecular condensates can modulate lipid membrane packing through wetting.
• Protein structural rearrangements influence condensate properties and water dynamics.
• Condensate-membrane interactions offer a general mechanism for tuning membrane properties in biological systems.