Linked Life Data

12950178

Source:http://linkedlifedata.com/resource/pubmed/id/12950178

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
35
pubmed:dateCreated
2003-9-2
pubmed:abstractText
Precipitation of the 39-43-residue amyloid beta peptide (Abeta) is a crucial factor in Alzheimer's disease (AD). In normal as well as in AD-afflicted brain, the Abeta concentration is estimated to be a few nanomolar. Here we show that Abeta(1-40) precipitates in vitro only if the dissolved concentration is >14 microM. Using fluorescence correlation spectroscopy, we further show that the precipitation is complete in 1 day, after which the size distribution of Abeta monomer/oligomers in the solution phase becomes stationary in time and independent of the starting Abeta concentration. Mass spectra confirm that both the solution phase and the coexisting precipitate contain chemically identical Abeta molecules. Incubation at 68 degrees C for 1 h reduces the solubility by <12%. Together, these results show that the thermodynamic saturation concentration (C(sat)) of Abeta(1-40) in phosphate-buffered saline (PBS) at pH 7.4 has a well-defined lower limit of 15.5 +/- 1 microM. Divalent metal ions (believed to play a role in AD) at near-saturation concentrations in PBS reduce C(sat) only marginally (2 mM Mg(2+) by 6%, 2.5 microM Ca(2+) by 7%, and 4 microM Zn(2+) by 11%). Given that no precipitation is possible at concentrations below C(sat), we infer that coprecipitant(s), and not properties of Abeta(1-40) alone, are key factors in the in vivo aggregation of Abeta.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10506-13
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
The amyloid beta peptide (Abeta(1-40)) is thermodynamically soluble at physiological concentrations.
pubmed:affiliation
Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't