Fig. 5.
Optimization of alkylation conditions. (A) Effects of the iodoacetamide concentration on the identification of proteins and peptides. (B) The number of identified peptides with alkylated cysteine, free cysteine (due to incomplete reaction), or the side reactions on the peptide N-terminus and the side chains of lysine and aspartic acid as a function of the iodoacetamide concentration. (C) Effects of the alkylation temperature on the identification of proteins and peptides. (D) The number of identified peptides with alkylated cysteine, free cysteine, or the side reactions on the peptide N-terminus and the side chains of lysine and aspartic acid at different alkylation temperatures.