Related Experiment Video
Updated: Jun 15, 2026

Phase Behavior of Charged Vesicles Under Symmetric and Asymmetric Solution Conditions Monitored with Fluorescence Microscopy
Published on: October 24, 2017
Temperature-dependent phase behavior and protein partitioning in giant plasma membrane vesicles
S A Johnson1, B M Stinson, M S Go
1Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA.
None:
Liquid-ordered (Lo) and liquid-disordered (Ld) phase coexistence has been suggested to partition the plasma membrane of biological cells into lateral compartments, allowing for enrichment or depletion of functionally relevant molecules. This dynamic partitioning might be involved in fine-tuning cellular signaling fidelity through coupling to the plasma membrane protein and lipid composition. In earlier work, giant plasma membrane vesicles, obtained by chemically induced blebbing from cultured cells, were observed to reversibly phase segregate at temperatures significantly below 37 degrees C. In this contribution, we compare the temperature dependence of fluid phase segregation in HeLa and rat basophilic leukemia (RBL) cells. We find an essentially monotonic temperature dependence of the number of phase-separated vesicles in both cell types. We also observe a strikingly broad distribution of phase transition temperatures in both cell types. The binding of peripheral proteins, such as cholera toxin subunit B (CTB), as well as Annexin V, is observed to modulate phase transition temperatures, indicating that peripheral protein binding may be a regulator for lateral heterogeneity in vivo. The partitioning of numerous signal protein anchors and full length proteins is investigated. We find Lo phase partitioning for several proteins assumed in the literature to be membrane raft associated, but observe deviations from this expectation for other proteins, including caveolin-1.
More Related Videos
Related Concept Videos
Membrane Fluidity
Membrane Fluidity
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
Phase Transitions: Melting and Freezing
Protein Diffusion in the Membrane
Asymmetric Lipid Bilayer
Enlargement of the Plasma Membrane

