Table I

Quantitation of N-isotag-labeled peptides from dephosphorylated recombinant Rad53 mixed in a 1:1 (light-to-heavy N-isotag-labeled) ratio

Data are shown for three independent experiments. The amino acid preceding the N terminus of the peptide is indicated in parenthesis with the exception of the N-terminal peptide of the protein.

PeptideExperiment 1Experiment 2Experiment 3
Ratio (d0/d6)Error (%)aRatio (d0/d6)Error (%)aRatio (d0/d6)Error (%)a
(K)KPPVSDTNNNGNNSVLNDLVESPINANTGNILK0.79−21.000.88−12.000.77−23.00
(R)DFIDSLLQVDPNNR0.80−20.000.95−5.000.90−10.00
(R)DLKPDNILIEQDDPVLVK0.80−20.000.91−9.000.91−9.00
(K)MSPLGSQSYGDFSQISLSQSLSQQK0.80−20.000.95−5.000.96−4.00
(R)IHSVSLSQSQIDPSKK0.82−18.000.84−16.000.92−8.00
(R)IHSVSLSQSQIDPSK0.84−16.000.86−14.000.96−4.00
(R)KLQMEQQLQEQDQEDQDGK0.85−15.000.93−7.000.92−8.00
(K)LDQTSKb0.88−12.000.99−1.001.022.00
(K)QCLEQNK0.90−10.001.055.001.033.00
(R)VHCFIFK0.91−9.000.82−18.000.88−12.00
(R)YTQPKb0.92−8.001.099.001.1010.00
(R)ELEVLQK0.93−7.001.055.001.044.00
(R)GKDTSVSPDEYEER0.93−7.001.011.000.87−13.00
(K)VQGNGSFMK0.93−7.001.066.001.099.00
(R)NPACDYHLGNISR0.94−6.001.022.001.055.00
(R)QILTAIK0.94−6.001.077.001.033.00
(K)LTQMMAAQR0.96−4.001.000.000.92−8.00
(K)DFSIIDEVVGQGAFATVK0.98−2.001.022.001.011.00
(K)FLLQDGDEIK0.99−1.001.066.001.000.00
(K)LLHSNNTENVK0.99−1.000.87−13.000.98−2.00
(K)VEINDTTGLFNEGLGMLQEQR1.022.001.099.000.95−5.00
(K)FVIGFKb1.033.000.97−3.001.066.00
(R)ANQPSASSSSMSAK1.044.000.94−6.001.066.00
(K)NNKFVIGFK1.044.000.98−2.001.099.00
(K)SIEAETR1.044.001.1313.001.1919.00
(K)ITDFGLAK1.055.001.044.001.000.00
(K)VIGNMDGVTR1.066.001.088.001.022.00
(R)DLSADISQVLK1.077.000.87−13.000.95−5.00
(K)DTSVSPDEYEER1.1111.001.1818.001.1111.00
(K)QCLEQNKVDR1.1111.001.2222.001.1818.00
(K)IIWDKb1.1212.001.011.000.97−3.00
(K)LLENMDDAQYEFVK1.1212.001.1515.001.088.00
(R)FLIEK1.1515.001.066.001.055.00
(K)IASPGLTSSTASSMVANK1.1616.001.1010.001.1010.00
(R)VICTTGQIPIR1.2121.001.1717.001.1010.00
MENITQPTQQSTQATQR1.2222.001.099.001.1111.00
Statistical averagec0.98−1.531.011.421.011.06
  • a Deviation from the expected value of 1.0.

  • b Peptides that are only identified from the N-isotag-labeled Rad53 (absent in the analysis of unlabeled Rad53). They are usually short peptides for which the N-isotag increases the mass so it is better analyzed by the LCQ ion trap instrument, which has a mass window between 400 and 1600 amu.

  • c An average of the ratios for all the identified peptides in each experiment.