Related Experiment Video
Updated: Aug 8, 2025
08:10
In Vitro Reconstitution of Self-Organizing Protein Patterns on Supported Lipid Bilayers
Published on: July 28, 2018
12.3K
OxPAPC stabilizes liquid-ordered domains in biomimetic membranes
Andres T Cavazos1, Edward Ross Pennington2, Sahil Dadoo2
1Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis Indiana.
Biophysical Journal
|February 25, 2023
Summary
Oxidized long-chain polyunsaturated fatty acids (PUFAs) alter cell membrane structure. Specifically, oxidized 1-palmitoyl-2-arachidonyl-phosphatidylcholine (oxPAPC) disrupts lipid packing and stabilizes liquid-ordered domains, potentially regulating inflammatory signaling.
Area of Science:
- Biochemistry
- Cell Biology
- Membrane Biophysics
Background:
- Long-chain polyunsaturated fatty acids (PUFAs) are susceptible to oxidation, forming oxidized PUFAs (oxPUFAs).
- Phospholipids containing oxPUFAs are implicated in regulating inflammatory responses.
- The precise mechanisms by which oxPUFAs influence cellular functions, particularly membrane organization, remain largely unknown.
Purpose of the Study:
- To investigate how oxidized 1-palmitoyl-2-arachidonyl-phosphatidylcholine (oxPAPC) affects the molecular organization of biomimetic membranes.
- To test the hypothesis that oxPAPC alters membrane architecture, specifically the structure of liquid-ordered (Lo) domains.
Main Methods:
- Utilized solid-state 2H Nuclear Magnetic Resonance (NMR) spectroscopy.
- Examined biomimetic membranes composed of lipid mixtures including cholesterol and either 1-palmitoyl-2-arachidonyl-phosphatidylcholine (PAPC) or oxPAPC.
Main Results:
- Replacing PAPC with oxPAPC disrupted the molecular organization within tightly packed Lo phases, indicating poor mixing.
- oxPAPC stabilized Lo domains formed by specific phospholipid and cholesterol mixtures.
- oxPAPC decreased molecular order in the surrounding liquid-disordered regions of the membrane.
Conclusions:
- Oxidized PUFAs, specifically oxPAPC, can alter membrane architecture by disrupting lipid packing and modulating domain stability.
- oxPAPC appears to stabilize Lo domains by disordering adjacent liquid-disordered regions.
- These structural changes in membrane domains may represent a mechanism for oxPAPC's role in regulating inflammatory signaling.
Related Concept Videos
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
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
01:26Membrane 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
01:35Asymmetric 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
01:19Fluid Mosaic Model
12.1K
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...
12.1K