Related Experiment Video
Updated: Aug 14, 2026

Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein
Published on: October 12, 2017
Oxidation of cholesterol catalyzed by amyloid beta-peptide (Abeta)-Cu complex on lipid membrane
Noriko Yoshimoto1, Makoto Tasaki, Toshinori Shimanouchi
1Department of Chemical Science and Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan.
Abstract:
A catalytic reaction of H2O2 production by an amyloid beta-peptide (Abeta)-Cu complex with cholesterol incorporated in a liposome was kinetically analyzed. The Michaelis-Menten model was applied to the H2O2 production reaction using cholesterol as the substrate catalyzed by the Abeta-Cu complex. The Km value for the Abeta-Cu complex catalytic reaction with cholesterol-containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes (Km=0.436 microM for Abeta(1-40); Km=0.641 microM for Abeta(1-42)) was found to be smaller than that with cholesterol-containing 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes (Km=0.585 microM for Abeta(1-40), Km=0.890 microM for Abeta(1-42)). The results imply that membrane properties could play an important role in the interactions of the Abeta-Cu complex with cholesterol in these liposomes. Considering the physical states of the cholesterol/POPC (liquid disordered phase) and cholesterol/DPPC (liquid ordered phase) liposomes in the present reaction conditions, the data obtained suggests that the H2O2-generating activity of the Abeta-Cu complex, accompanied by oxidation of membrane-incorporated cholesterol, could be effected by the phase of the liposome membranes.
Related Concept Videos
Receptor-mediated Endocytosis
Amyloid Fibrils
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
Amyloid Fibrils
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
Oxidation of Phenols to Quinones
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 property is crucial in...
Reactions of Aldehydes and Ketones: Baeyer–Villiger Oxidation
The carbonyl center is activated by...
Lipid Absorption
These breakdown products bind with bile salts and lecithin to form micelles, which quickly pass between microvilli to come in close contact with the apical...

