title: Qualification and application of a liquid chromatography-tandem mass spectrometric method for the determination of human Aβ1-40 and Aβ1-42 peptides in transgenic mouse plasma using micro-elution solid phase extraction.
abstract: A liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed and applied for the determination of human Aβ1-40 and Aβ1-42 peptides in transgenic mouse plasma to support preclinical pharmacodynamics studies. The method consisted of micro-elution solid phase extraction for sample preparation and LC-MS/MS analysis in the negative ion mode using electrospray ionization for analysis. (15)N53-Aβ1-40 and (15)N55-Aβ1-42 peptides were used as internal standards. A quadratic regression (weighted 1/concentrations), with an equation y = ax(2) + bx + c, was used to fit calibration curves over the concentration range of 0.500-100 ng/mL for both Aβ1-40 and Aβ1-42 peptides. For quality control samples at 6.00, 40.0 and 80.0 ng/mL from the qualification experiment, the within-run accuracy ranged from -2.69 to 0.583 % with precision values ≤8.23 % for Aβ1-40. Within-run accuracy ranged from -4.83 to 10.1 % with precision values ≤8.87 % for Aβ1-42. Samples from a pharmacodynamics study using Tg2576 transgenic mice were analyzed by this qualified LC-MS/MS method and concentrations were compared to those generated by ELISA. The two methods were shown to be comparable for Aβ1-40 quantification of samples from the Tg2576 amyloid precursor protein transgenic mouse model, but varied slightly for Aβ1-42.
authors.affiliation: Drug Metabolism and Pharmacokinetics, Genentech Inc., 1 DNA Way, Mail Stop 412A, South San Francisco, CA, 94080, USA, yshin@cnu.ac.kr.
authors.forename: Young G
authors.initials: YG
authors.lastname: Shin
authors.forename: Lee
authors.initials: L
authors.lastname: Hamm
authors.forename: Stanley
authors.initials: S
authors.lastname: Murakami
authors.forename: Kenji
authors.initials: K
authors.lastname: Buirst
authors.forename: Michael H
authors.initials: MH
authors.lastname: Buonarati
authors.forename: April
authors.initials: A
authors.lastname: Cox
authors.forename: Kelly
authors.initials: K
authors.lastname: Regal
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Hunt
authors.forename: Kimberly
authors.initials: K
authors.lastname: Scearce-Levie
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Watts
authors.forename: Xingrong
authors.initials: X
authors.lastname: Liu
mesh_terms: D016229:Amyloid beta-Peptides / Q000097:blood* / Q000235:genetics; D000818:Animals; D002138:Calibration; D002853:Chromatography, Liquid / Q000592:standards; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010446:Peptide Fragments / Q000097:blood* / Q000235:genetics; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D052617:Solid Phase Microextraction / Q000592:standards; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry / Q000592:standards
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42)