Dynamic Shape Modulation of Deflated and Adhered Lipid Vesicles

Area of Science:

• Biophysics
• Cell Biology
• Membrane Biophysics

Background:

• Organelles have complex shapes crucial for function.
• Reproducing organelle morphology in vitro is challenging.
• Small reduced volumes are characteristic of organelles like Golgi cisternae.

Purpose of the Study:

• To develop an in vitro method to create organelle-like shapes.
• To quantitatively study membrane mechanics and shape determination.
• To investigate mechanisms of curvature-mediated protein sorting.

Main Methods:

• Osmotic deflation of giant unilamellar vesicles (GUVs).
• Application of the Canham-Helfrich model for shape analysis.
• Determination of mechanical parameters: adhesion strength, membrane tension, and pressure.

Main Results:

• Achieved reduced volumes as low as 0.1 in GUVs, mimicking organelle shapes.
• Identified normalized adhesion strength as key to shape flattening rate.
• Established a geometric relationship to estimate adhesion strength from vesicle geometry.

Conclusions:

• Developed a quantitative experimental platform for studying membrane shaping.
• Provides insights into organelle morphology and its functional implications.
• Enables bottom-up investigation of shape-dependent phenomena like protein sorting.