Related Experiment Video
Updated: Apr 5, 2026
07:29
Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein
Published on: October 12, 2017
9.9K
Lipid Peroxidation in Membranes: The Peroxyl Radical Does Not "Float"
Julian Garrec1,2, Antonio Monari1,2, Xavier Assfeld1,2
1†Théorie-Modélisation-Simulation, SRSMC, CNRS, Vandoeuvre-lès-Nancy F-54506, France.
The Journal of Physical Chemistry Letters
|August 14, 2015
Summary
The "floating peroxyl radical" hypothesis in lipid peroxidation is incorrect. Molecular modeling shows peroxyl radicals remain deep within cell membranes, not at the surface, impacting disease and antioxidant design.
Area of Science:
- Biochemistry
- Cell Biology
- Physical Chemistry
Background:
- Lipid peroxidation is a key process in many diseases.
- The precise location of radical reactions within cell membranes is not fully understood.
- A prevailing hypothesis suggests peroxyl radicals diffuse to the membrane surface, limiting reaction propagation.
Purpose of the Study:
- To investigate the validity of the "floating peroxyl radical" hypothesis.
- To determine the actual location of peroxyl radicals during lipid peroxidation in bilayers.
- To inform the development of targeted antioxidants.
Main Methods:
- Utilized molecular modeling techniques.
- Performed quantum calculations on model systems.
- Conducted atomistic simulations of lipid bilayers with oxidation products.
Main Results:
- Demonstrated that peroxyl radicals do not "float" at the membrane surface.
- Showed peroxyl radicals remain localized deep within the lipid bilayer.
- Challenged the established understanding of radical propagation in membranes.
Conclusions:
- The "floating peroxyl radical" hypothesis is not supported by this study.
- Findings necessitate a re-evaluation of cellular protection mechanisms against peroxidation.
- Results provide a basis for designing more effective, localized antioxidants.
More Related Videos
Related Concept Videos
01:20Radical Autoxidation
3.4K
The oxidation of an organic compound in the presence of air or oxygen is called autoxidation. For example, cumene reacts with oxygen to form hydroperoxide. Autoxidation involves initiation, propagation, and termination steps. Many organic compounds are susceptible to autoxidation—especially ethers in the presence of oxygen, which form hydroperoxides. Even though this reaction is slow, old ether bottles contain small amounts of peroxide, which leads to laboratory explosions during ether...
3.4K
01:24Peroxisomes
22.2K
Peroxisomes are specialized organelles present in fungi, plant, and animal cells. It can vary in number, size, morphology, and activity depending on the type of tissue and the nutritional state of the cell. For example, cells with active lipid metabolism, such as adipocytes, neurons, and hepatocytes, have more peroxisomes than other cells in the body. Besides their primary role in breaking down complex organic molecules, peroxisomes can also synthesize specific macromolecules and participate in...
22.2K
01:24Peroxisomes
2.0K
2.0K
02:23Autoxidation of Ethers to Peroxides and Hydroperoxides
10.1K
Ethers represent a class of chemical compounds that become more dangerous with prolonged storage because they tend to form explosive peroxides when standing in the air. Autoxidation is the spontaneous oxidation of a compound in air. In the presence of oxygen, ethers slowly oxidize to form hydroperoxides and dialkyl peroxides.
10.1K
01:27Protein Import into the Peroxisomes
5.7K
Cells contain membrane-bound organelles called peroxisomes that oxidize organic molecules by transferring hydrogen atoms to oxygen, producing hydrogen peroxide. Peroxisomes enzymatically convert the released hydrogen peroxide into water and oxygen.
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
5.7K
01:17Oxidation of Phenols to Quinones
5.3K
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
5.3K