Journal
MICRON
Volume 39, Issue 8, Pages 1192-1196Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.micron.2008.05.001
Keywords
Amyloid-beta (A beta); Cholesterol; Fibril; Cholesterol-PEG 600; Micelle; Cholesterol microcrystal; Negative staining
Categories
Ask authors/readers for more resources
There is increasing interest in the role of brain cholesterol in Alzheimer's disease and the contribution of cholesterol to the formation of amyloid plaques. This paper presents a TEM study showing the binding of soluble similar to 10 nm diameter cholesterol-PEG 600 micelles to amyloid-beta(1-42) (A beta(1-42)) fibrils formed either in the presence of this cholesterol derivative or to preformed fibrils generated under four different fibrillogenesis conditions. Specimens negatively stained with uranyl acetate revealed that during 24 h fibrillogenesis at 37 degrees C the cholesterol-PEG micelles bound periodically to A beta(1-42) protofibrils and apparently also formed a thin smooth unbroken coating on mature double helical fibrils. Preformed protofibrils, generated in water alone or in the presence of 0.1 mM cupric sulphate, also exhibited periodic binding of cholesterol-PEG micelles, indicating the inherently helical nature of the protofibril. Double helical mature A beta(1-42) fibrils, generated in the presence of cholesterol microcrystals or hydrogen peroxide (I mM), bound cholesterol-PEG micelles with no immediately apparent regularity and without creating a smooth coating. The differing capacities of the A beta(1-42) protofibrils and mature double helical fibrils to bind cholesterol-PEG 600 may indicate differences in the accessibility of the micellar cholesterol to the purported A beta(17-21) hydrophobic cholesterol-binding motif on the fibril surfaces. (C) 2008 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available