Figure 1

The reaction flow of the applied labelling method. The carboxyl amino acid side chains of Bovine Serum Albumin model protein were activated by EDC and Sulfo-NHS, and then biotinylated by Biotinyl Cystamine. During the nanoLC-MS/MS sample preparation, the disulphide bridges were cleaved by DTT and alkylated by Iodoacetamide reagents.