Dynamic correlations in lipid bilayer membranes over finite time intervals
Rafael L Schoch1, Gilad Haran1, Frank L H Brown2
1Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel.
The Journal of Chemical Physics
|February 1, 2023
Summary
Dynamic lipid-lipid correlations in membranes are influenced by measurement timescales. Theoretical models explain how finite acquisition times affect observed correlations, aligning with simulations and suggesting new avenues for membrane protein studies.
Area of Science:
- Biophysics
- Physical Chemistry
- Materials Science
Background:
- Recent single-molecule measurements reveal dynamic lipid-lipid correlations in biological membranes.
- Observed correlations possess submicrometer spatial and submillisecond temporal resolution.
- These experimental scales are significantly longer than intrinsic molecular motions.
Purpose of the Study:
- To derive theoretical expressions for experimentally measurable correlations from the two-body diffusion matrix.
- To account for the effects of temporal and spatial averaging due to finite acquisition times.
- To compare theoretical predictions with Brownian dynamics simulations and experimental data.
Main Methods:
- Derivation of theoretical expressions for lipid-lipid correlations.
- Analysis of the two-body diffusion matrix for membrane-bound molecules with hydrodynamic interactions.
- Brownian dynamics simulations to model experimental measurements.
Main Results:
- Finite acquisition times lead to the "washing out" of correlations compared to instantaneous measurements.
- Theoretical predictions show excellent agreement with Brownian dynamics simulations.
- The derived theoretical framework accurately describes the observed lipid-lipid correlations.
Conclusions:
- Experimental measurement timescales significantly impact the observation of dynamic lipid-lipid correlations.
- Theoretical modeling provides a framework to interpret experimental results considering acquisition limitations.
- Complementary measurements of membrane protein diffusion may resolve ambiguities in black lipid membrane studies.
More Related Videos
10:02Neutron Spin Echo Spectroscopy as a Unique Probe for Lipid Membrane Dynamics and Membrane-Protein Interactions
Published on: May 27, 2021
4.1K
08:55Single-Molecule Imaging of Lateral Mobility and Ion Channel Activity in Lipid Bilayers using Total Internal Reflection Fluorescence TIRF Microscopy
Published on: February 17, 2023
3.2K
Related Concept Videos
01:35Asymmetric Lipid Bilayer
7.4K
Biological membranes show uneven distribution of different types of lipids in the inner and outer layers, resulting in transverse asymmetric membranes. The treatment of the erythrocyte membrane with the enzyme phospholipase confirmed the asymmetric nature of the lipid bilayer. The enzyme hydrolyzes lipids into fatty acids and hydrophilic groups. The phospholipase acts only on the outer layer of the membrane, while the inner layer remains intact. The phospholipase treatment resulted in 80%...
7.4K
01:24Protein Diffusion in the Membrane
4.5K
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
4.5K
01:26Membrane Fluidity
11.4K
Membrane fluidity is explained by the fluid mosaic model of the cell membrane, which describes the plasma membrane structure as a mosaic of components—including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character.
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...
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...
11.4K
01:19Fluid Mosaic Model
12.2K
Scientists identified the plasma membrane in the 1890s and its principal chemical components (lipids and proteins) by 1915. The model for plasma membrane structure, proposed in 1935 by Hugh Davson and James Danielli, was the first model to be widely accepted in the scientific community. The model was based on the plasma membrane's "railroad track" appearance in early electron micrographs. Davson and Danielli theorized that the plasma membrane's structure resembled a sandwich...
12.2K
00:59Mechanisms of Membrane Domain Formation
3.1K
Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with...
Another mechanism for membrane domain formation involves membrane proteins interacting with...
3.1K
01:18Membrane Domains
5.5K
The membrane domains concentrate specific lipids and proteins at one place within the membrane, which helps in cell signaling, adhesion, and other critical cellular processes. These domains can differ in size, composition, function, and lifespan.
Protein Domains
The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the...
Protein Domains
The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the...
5.5K