title: Method for the simultaneous quantitation of apolipoprotein E isoforms using tandem mass spectrometry.
abstract: Using apolipoprotein E (ApoE) as a model protein, we developed a protein isoform analysis method utilizing stable isotope labeling tandem mass spectrometry (SILT MS). ApoE isoforms are quantitated using the intensities of the b and y ions of the (13)C-labeled tryptic isoform-specific peptides versus unlabeled tryptic isoform-specific peptides. The ApoE protein isoform analysis using SILT allows for the simultaneous detection and relative quantitation of different ApoE isoforms from the same sample. This method provides a less biased assessment of ApoE isoforms compared to antibody-dependent methods, and may lead to a better understanding of the biological differences between isoforms.
authors: Department of Neurology, Hope Center for Neurological Disorders and Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors: Kristin R
authors: KR
authors: Wildsmith
authors: Bomie
authors: B
authors: Han
authors: Randall J
authors: RJ
authors: Bateman
mesh_terms: D000544:Alzheimer Disease; D000818:Animals; D053329:Apolipoprotein E2 / Q000032:analysis / Q000235:genetics; D053327:Apolipoprotein E4 / Q000032:analysis / Q000235:genetics; D001057:Apolipoproteins E / Q000032:analysis*; D001253:Astrocytes; D002247:Carbon Isotopes; D002461:Cell Line, Transformed; D055879:Gene Knock-In Techniques; D007201:Indicator Dilution Techniques; D008074:Lipoproteins / Q000302:isolation & purification; D051379:Mice; D010446:Peptide Fragments / Q000032:analysis*; D020033:Protein Isoforms / Q000032:analysis*; D012307:Risk Factors; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014357:Trypsin
chemical_list: D053329:Apolipoprotein E2; D053327:Apolipoprotein E4; D001057:Apolipoproteins E; D002247:Carbon Isotopes; D008074:Lipoproteins; D010446:Peptide Fragments; D020033:Protein Isoforms; D014357:Trypsin