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Updated: Aug 28, 2025
09:38
Fabrication Procedures and Birefringence Measurements for Designing Magnetically Responsive Lanthanide Ion Chelating Phospholipid Assemblies
Published on: January 3, 2018
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Inhibitory Effect of Lanthanides on Native Lipid Flip-Flop
Victoria Cheng1, John C Conboy1
1Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States.
The Journal of Physical Chemistry. B
|September 21, 2022
Summary
Ytterbium ions (Yb3+) significantly alter lipid bilayer physical properties and inhibit lipid flip-flop by interacting with the headgroup. This interaction increases the energy barrier for lipid flip-flop, impacting membrane dynamics.
Area of Science:
- Biophysics
- Materials Science
- Chemical Biology
Background:
- Dipalmitoylphosphatidylcholine (DPPC) planar supported lipid bilayers (PSLBs) are model systems for cell membranes.
- Ytterbium ions (Yb3+) are paramagnetic NMR chemical shift reagents with known interactions with biological molecules.
Purpose of the Study:
- To investigate the influence of Yb3+ on the physical properties and flip-flop kinetics of DPPC PSLBs.
- To elucidate the mechanism of Yb3+ interaction with DPPC lipid bilayers.
Main Methods:
- Langmuir isotherm studies to assess lipid-lipid interactions and membrane elasticity.
- Sum-frequency vibrational spectroscopy to probe acyl chain ordering and phase transitions.
- Analysis of flip-flop kinetics using transition state theory.
Main Results:
- Yb3+ strongly interacts with the DPPC phosphate headgroup, increasing membrane shear and compression moduli.
- Acyl chain ordering and phase transition temperatures are altered by Yb3+, with concentration-dependent effects observed.
- DPPC flip-flop kinetics are substantially inhibited in the presence of Yb3+, with increased free energy barriers in both gel and liquid crystalline phases.
- Evidence suggests Yb3+ may form complexes with Tris buffer, further coordinating to the PC headgroup.
Conclusions:
- Yb3+ significantly modifies the physical properties of lipid membranes.
- The interaction of Yb3+ with the DPPC headgroup leads to a pronounced inhibition of lipid flip-flop.
- Yb3+ interaction effectively modifies headgroup charge, impacting membrane dynamics and flip-flop mechanisms.
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