Glycans pattern the phase behaviour of lipid membranes

Area of Science:

• Biochemistry
• Cell Biology
• Materials Science

Background:

• Hydrated glycan networks (polysaccharides) are abundant extracellularly, adjacent to cellular plasma membranes.
• The precise function of these extracellular glycans remains largely uncharacterized.

Purpose of the Study:

• To investigate the role of glycan spatial configuration in modulating the phase behavior of model lipid membranes.
• To determine the thermodynamic basis and molecular interactions underlying glycan-induced membrane patterning.

Main Methods:

• Utilized multiphase model lipid membranes to study glycan network effects.
• Analyzed lipid domain formation and phase separation under varying glycan network configurations.
• Assessed the thermal reversibility of glycan-patterned phase separation.

Main Results:

• Inhomogeneous glycan networks stabilized large lipid domains at the network's characteristic length scale.
• Homogeneous glycan networks suppressed macroscopic lipid phase separation.
• Glycan-patterned phase separation was found to be thermally reversible, indicating a thermodynamic process.
• Phase patterning likely arises from preferential interactions between glycans and ordered lipid phases.

Conclusions:

• The spatial arrangement of extracellular glycans critically controls lipid membrane phase behavior.
• Glycan-membrane interactions can lead to thermodynamically driven lipid domain organization.
• Findings suggest a significant coupling between cellular lipidomes and glycomes, with implications for membrane transport and native vs. model membrane behavior.