Related Experiment Video
Updated: Jun 15, 2025
Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy
Published on: August 13, 2019
Issues with lipid probes in flip-flop measurements: A comparative study using sum-frequency vibrational spectroscopy
Joshua M Taylor1, John C Conboy1
1Department of Chemistry, University of Utah, 315 South 1400 East RM. 2020, Salt Lake City, Utah 84112, USA.
Fluorescent lipid probes like C6 NBD-PC do not accurately reflect native lipid flip-flop kinetics. Their behavior is significantly influenced by the surrounding lipid matrix, as shown by sum-frequency vibrational spectroscopy.
Area of Science:
- Membrane biophysics
- Lipid dynamics
- Spectroscopic analysis
Background:
- Fluorescent lipid probes are widely used to study lipid flip-flop kinetics.
- The accuracy of these probes in representing native lipid behavior remains unverified.
Purpose of the Study:
- To evaluate the reliability of C6 NBD-PC as a reporter for native lipid translocation.
- To compare the flip-flop kinetics of C6 NBD-PC with native lipids in different membrane environments.
Main Methods:
- Sum-frequency vibrational spectroscopy (SFVS) to measure lipid flip-flop kinetics and acyl chain order.
- Second-harmonic generation (SHG) spectroscopy to probe NBD chromophore motion.
- Investigation of C6 NBD-PC in DPPC and DSPC lipid bilayers at varying concentrations.
Main Results:
- C6 NBD-PC exhibited faster flip-flop kinetics than native lipids in both DPPC and DSPC matrices.
- The probe's behavior was significantly altered in a chain-mismatched DSPC environment, showing increased disorder.
- SFVS and SHG measurements of flip-flop kinetics were consistent.
Conclusions:
- C6 NBD-PC is not an adequate mimic of native lipid behavior in membranes.
- The lipid matrix composition profoundly impacts the translocation dynamics of fluorescent lipid probes.
More Related Videos
07:11Dissipative Microgravimetry to Study the Binding Dynamics of the Phospholipid Binding Protein Annexin A2 to Solid-supported Lipid Bilayers Using a Quartz Resonator
Published on: November 1, 2018
12:15Single Liposome Measurements for the Study of Proton-Pumping Membrane Enzymes Using Electrochemistry and Fluorescent Microscopy
Published on: February 21, 2019
Related Concept Videos
01:25Fluorescence and Phosphorescence: Instrumentation
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...