Fig. 3

Labeling efficiency of IDN assay compared to IN control. IDN: reduced Cys were labeled with IAM and reversibly-oxidized Cys were reduced with DTT prior to labeling with NEM. IN: reduced Cys were first labeled with IAM and then with NEM without reduction between steps. The labeled Cys-containing peptides and Cys residues were quantified in samples harvested at early-exponential phase (EEP), mid-exponential phase (MEP) and late-exponential phase (LEP). Data correspond to mean values calculated for triplicates. Error bars show standard deviation. Paired Student t-test was performed to determine statistical significance (*: 0.01 < p < 0.05; **: 0.001 < p < 0.01; ***: p < 0.001)