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High resolution scanning tunnelling microscopy of the β-amyloid protein (Aβ1-40) of Alzheimer's disease suggests a novel mechanism of oligomer assembly

Citation

Losic, D and Martin, LL and Mechler, A and Aguilar, MI and Small, DH, High resolution scanning tunnelling microscopy of the β-amyloid protein (Aβ1-40) of Alzheimer's disease suggests a novel mechanism of oligomer assembly, Journal of Structural Biology, 155, (1) pp. 104-110. ISSN 1047-8477 (2006) [Refereed Article]

DOI: doi:10.1016/j.jsb.2006.02.013

Abstract

The aggregation of the -amyloid protein (A) is an important step in the pathogenesis of Alzheimer's disease. There is increasing evidence that lower molecular weight oligomeric forms of A may be the most toxic species in vivo. However, little is known about the structure of A oligomers. In this study, scanning tunnelling microscopy (STM) was used to examine the structure of A monomers, dimers and oligomers. A1-40 was visualised by STM on a surface of atomically flat gold. At low concentrations (0.5 M) small globular structures were observed. High resolution STM of these structures revealed them to be monomers of A. The monomers measured approximately 3-4 nm in diameter. Internal structure was seen in many of the monomers consistent with a conformation in which the polypeptide chain is folded into 3 or 4 domains. Oligomers were seen after ageing the A solution for 24 h. The oligomers were also 3-4 nm in width and appeared to be formed by the end-to-end association of monomers with the polypeptide chain oriented at 90 to the axis of the oligomer. The results suggest that the oligomer formation can proceed through a mechanism involving the linear association of monomers.

Item Details

Item Type:Refereed Article
Research Division:Medical and Health Sciences
Research Group:Neurosciences
Research Field:Neurosciences not elsewhere classified
Objective Division:Health
Objective Group:Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:Neurodegenerative Disorders Related to Ageing
Author:Small, DH (Professor David Small)
ID Code:61092
Year Published:2006
Web of Science® Times Cited:45
Deposited By:Menzies Institute for Medical Research
Deposited On:2010-02-25
Last Modified:2010-09-16
Downloads:0

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