Identification of Disulfide-Linked Peptides by LC-MALDI Using Extracted Fragment Chromatograms

The intact three dimensional structure of proteins is essential for their biological function. Important to the stability of the tertiary structure are intra-molecular disulfide bonds. The structure of proteins is dynamic and important biological processes like protein-protein interactions or enzyme-substrate binding can lead to a change in the tertiary structure, which may result in the cleavage and reconnection of disulfide bridges. The identification and characterization of disulfide bridges is therefore a very important tool for the investigation of such processes. Here we present a way to identify and characterize disulfide bridges using an LC-MALDI workflow and extracting fragment ion chromatograms.