The formation of disulfide bridges in proteins is an important post-translational modification that is critical for stabilizing the native structures of proteins. The disulfide linkages in a protein cannot be predicted from its aminoacid sequence; therefore, determination of disulfide bridges linkages in the protein will provide insights into its three-dimensional structure and contribute to the understanding of its structural-functional relationship. The determination of the number and position of the disulfide bridges is one of the requirements for the characterization of the biological products included in the ICH Q6B.
The procedure for the determination of disulfide bridges employed by AMSbiopharma consists of comparing the peptide mapping obtained under reducing and non-reducing conditions of your antibody or protein digested. Peptides without disulfide bridges will appear in both chromatograms, while peptides with disulfide bridges will appear as new peaks in the chromatogram of the non-reducing conditions and will disappear as reduced peptides from the chromatogram of reducing conditions.