Ford MJ, Cantone JL, Polson C, Toyn JH, Meredith JE, Drexler DM.
J Neurosci Methods. 2008 Mar 15;168(2):465-74.
Targeting the metabolism of amyloid beta peptides (Abeta) is currently the leading experimental approach to treatment of Alzheimer's disease (AD). Described here is an immunoprecipitation-liquid chromatography/mass spectrometry (ip-LC/MS) assay to simultaneously characterize and quantitate different forms of Abeta in biological samples. The 4G8 antibody, specific for the 17-24 amino acid epitope of Abeta was employed to selectively isolate Abeta from in vitro samples for subsequent LC-MS analysis. A high resolution accurate mass hybrid linear ion trap-Orbitrap, LTQ-Orbitrap mass spectrometer was used to identify forms of 12 Abeta in H4-APP751 swe cell extracts based on ab initio calculations, accurate mass measurements, isotopic modeling and by de novo peptide sequencing using tandem mass spectrometry. The quantitative LC-MS analysis was performed on a linear ion trap mass spectrometer, LTQ, in full scan mode, this mode of operation enables sensitive detection levels and post-acquisition data mining for different forms of Abeta for quantitative assessment. Dosing studies with three known inhibitors of Abeta production, sulindac sulfide (SSide), BMS-299897 ('897) and compound W (CW) are reported to demonstrate the utility and analytical characteristics of the assay. This assay has the potential to provide insight into the formation of Abeta; increase understanding of drug mechanisms; and to contribute to drug efficacy studies.
http://www.sciencedirect.com/science/article/pii/S0165027007005663Bristol-Myers Squibb Company, Research and Development, Bioanalytical and Discovery Analytical Sciences, Wallingford, CT 06492, United States.
United States
