Premium
18 O‐labeling quantitative proteomics using an ion trap mass spectrometer
Author(s) -
Sakai Jun,
Kojima Shinich,
Yanagi Kazunori,
Kanaoka Masaharu
Publication year - 2005
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.200300885
Subject(s) - mass spectrometry , ion trap , proteomics , top down proteomics , hybrid mass spectrometer , chemistry , trap (plumbing) , quantitative proteomics , ion , quadrupole ion trap , selected reaction monitoring , analytical chemistry (journal) , chromatography , tandem mass spectrometry , physics , biochemistry , gene , organic chemistry , meteorology
We describe a method for simultaneous identification and quantitation of proteins within complex mixtures. The method consists of 18 O‐labeling, a simple stable isotope‐coding that requires merely enzymatic digestion in 18 O‐water, in combination with a capillary‐liquid chromatography electrospray ion‐trap mass spectrometer. In a separate experiment using the same sample and a spike test, we demonstrate that the difference ratio was calculated accurately using the 18 O‐labeling method even if the protein was part of a complex mixture. Our data also suggest that the accuracy of the quantitation can be improved by averaging the difference ratios of several peptides. In comparing our method with the isotope‐coded affinity tag (ICAT) method, we show that the 18 O‐labeling method has the advantages of better recovery and fewer isotope effects. Therefore, the 18 O‐labeling method is a powerful tool for large‐scale proteomics applications.