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Quantification of the Concentration of A beta 42 Propagons during the Lag Phase by an Amyloid Chain Reaction Assay

Arosio, Paolo; Cukalevski, Risto LU ; Frohm, Birgitta LU ; Knowles, Tuomas P. J. and Linse, Sara LU (2014) In Journal of the American Chemical Society 136(1). p.219-225
Abstract
The aggregation of the amyloid beta peptide, A beta 42, implicated in Alzheimer's disease, is characterized by a lag phase followed by a rapid growth phase. Conventional methods to study this reaction are not sensitive to events taking place early in the lag phase promoting the assumption that only monomeric or oligomeric species are present at early stages and that the lag time is defined by the primary nucleation rate only. Here we exploit the high sensitivity of chemical chain reactions to the reagent composition to develop an assay which improves by 2 orders of magnitude the detection limit of conventional bulk techniques and allows the concentration of fibrillar A beta 42 propagons to be detected and quantified even during the lag... (More)
The aggregation of the amyloid beta peptide, A beta 42, implicated in Alzheimer's disease, is characterized by a lag phase followed by a rapid growth phase. Conventional methods to study this reaction are not sensitive to events taking place early in the lag phase promoting the assumption that only monomeric or oligomeric species are present at early stages and that the lag time is defined by the primary nucleation rate only. Here we exploit the high sensitivity of chemical chain reactions to the reagent composition to develop an assay which improves by 2 orders of magnitude the detection limit of conventional bulk techniques and allows the concentration of fibrillar A beta 42 propagons to be detected and quantified even during the lag time. The method relies on the chain reaction multiplication of a small number of initial fibrils by secondary nucleation on the fibril surface in the presence of monomeric peptides, allowing the quantification of the number of initial propagons by comparing the multiplication reaction kinetics with controlled seeding data. The quantitative results of the chain reaction assay are confirmed by qualitative transmission electron microscopy analysis. The results demonstrate the nonlinearity of the aggregation process which involves both primary and secondary nucleation events even at the early stages of the reaction during the lag-phase. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of the American Chemical Society
volume
136
issue
1
pages
219 - 225
publisher
The American Chemical Society
external identifiers
  • wos:000329586600044
  • scopus:84892178364
ISSN
1520-5126
DOI
10.1021/ja408765u
language
English
LU publication?
yes
id
7e2265c1-8e9f-4f2d-bf90-3bcc5d628911 (old id 4318999)
date added to LUP
2014-02-25 14:13:44
date last changed
2017-10-22 04:00:30
@article{7e2265c1-8e9f-4f2d-bf90-3bcc5d628911,
  abstract     = {The aggregation of the amyloid beta peptide, A beta 42, implicated in Alzheimer's disease, is characterized by a lag phase followed by a rapid growth phase. Conventional methods to study this reaction are not sensitive to events taking place early in the lag phase promoting the assumption that only monomeric or oligomeric species are present at early stages and that the lag time is defined by the primary nucleation rate only. Here we exploit the high sensitivity of chemical chain reactions to the reagent composition to develop an assay which improves by 2 orders of magnitude the detection limit of conventional bulk techniques and allows the concentration of fibrillar A beta 42 propagons to be detected and quantified even during the lag time. The method relies on the chain reaction multiplication of a small number of initial fibrils by secondary nucleation on the fibril surface in the presence of monomeric peptides, allowing the quantification of the number of initial propagons by comparing the multiplication reaction kinetics with controlled seeding data. The quantitative results of the chain reaction assay are confirmed by qualitative transmission electron microscopy analysis. The results demonstrate the nonlinearity of the aggregation process which involves both primary and secondary nucleation events even at the early stages of the reaction during the lag-phase.},
  author       = {Arosio, Paolo and Cukalevski, Risto and Frohm, Birgitta and Knowles, Tuomas P. J. and Linse, Sara},
  issn         = {1520-5126},
  language     = {eng},
  number       = {1},
  pages        = {219--225},
  publisher    = {The American Chemical Society},
  series       = {Journal of the American Chemical Society},
  title        = {Quantification of the Concentration of A beta 42 Propagons during the Lag Phase by an Amyloid Chain Reaction Assay},
  url          = {http://dx.doi.org/10.1021/ja408765u},
  volume       = {136},
  year         = {2014},
}