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P3–379: Characterizing the interaction between ABAD and Aβ using surface plasma resonance and nuclear magnetic resonance
Author(s) -
Wang Chunyu,
Yan Yilin,
Liu Yangzhong,
Yan Shirley ShiDu,
Xu Hong Wei
Publication year - 2006
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2006.05.1649
Subject(s) - nad+ kinase , binding site , biophysics , chemistry , cofactor , conformational change , in vivo , binding energy , biochemistry , enzyme , biology , physics , microbiology and biotechnology , nuclear physics
Our approach was to use the 2-D gel electrophoresis (2DGE) based proteomics workflow to compare the brain protein profiles between the 3-month old AD transgenic mice and their age-matched normal controls. Reproducible patterns with over 1400 protein spots were obtained for each sample on the 2-D gel. However, less than 10 showed differential expression, typically low abundance proteins. Those proteins were below the detection limit for identification using the liquid chromatography tandem mass spectrometry (LC/MS/MS) on an ion-trap mass spectrometer. Therefore, we applied several protein fractionation methods prior to the gel separation, for example micropreparative isoelectric focusing using the microRotofor, ion-exchange fractionation and preparative electrophoresis with the PrepCell. These efforts enriched the protein fractions with the differentially expressed proteins enough to allow confident LC-MS/MS identification. We identified a small heat shock protein with a cytoprotective function alphaB crystallin. We also confirmed the reduction of the alphaB crystallin expression in the AD transgenic mice brain compared to the control samples by Western blot analysis. In aged AD human brain, an up-regulation of alphaB crystallin appears associated with the APP-related protein accumulation and plaque formation. Our observation of downregulated protein level of the cytoprotective alphaB crystallin in the AD transgenic mouse brain at young age suggests a possible weakened neuroprotective response to the presence of mutant human APP in the brain at the early stage of the AD. In this presentation we will discuss both the methodology and the implications on current understanding of molecular disease pathway.