Title: Serum apolipoprotein A-1 quantification by LC-MS with a SILAC internal standard reveals reduced levels in smokers.
Authors: Wang, Qingqing; Zhang, Suhong; Guo, Lili; Busch, Christine M; Jian, Wenying; Weng, Naidong; Snyder, Nathaniel W; Rangiah, Kannan; Mesaros, Clementina; Blair, Ian A
Published In Bioanalysis, (2015)
Abstract: Absolute quantification of protein biomarkers such as serum apolipoprotein A1 by both immunoassays and LC-MS can provide misleading results.Recombinant ApoA-1 internal standard was prepared using stable isotope labeling by amino acids in cell culture with [(13)C6(15)N2]-lysine and [(13)C9(15)N1]-tyrosine in human cells. A stable isotope dilution LC-MS method for serum ApoA-1 was validated and levels analyzed for 50 nonsmokers and 50 smokers.The concentration of ApoA-1 in nonsmokers was 169.4 mg/dl with an 18.4% reduction to 138.2 mg/dl in smokers. The validated assay will have clinical utility for assessing effects of smoking cessation and therapeutic or dietary interventions in high-risk populations.
PubMed ID: 26394123
MeSH Terms: Adult; Aged; Aged, 80 and over; Amino Acid Sequence; Apolipoprotein A-I/blood*; Case-Control Studies; Chromatography, Liquid/methods*; Female; Humans; Immunoassay; Isotope Labeling/methods*; Male; Middle Aged; Molecular Sequence Data; Sequence Homology, Amino Acid; Smoking/physiopathology*; Tandem Mass Spectrometry/methods*