Invited Talk: Electrospray ionization ion trap mass spectrometry for cyclic peptide characterization

Sudarslal S, Ph.D.
Associate Professor, School of Biotechnology, Amrita University

Electrospray ionization ion trap mass spectrometry for cyclic peptide characterization

There has been considerable interest in the isolation and structural characterization of bioactive peptides produced by bacteria and fungi. Most of the peptides are cyclic depsipeptides characterized by the presence of lactone linkages and β-hydroxy fatty acids. Occurrence of microheterogeneity is another remarkable property of these peptides. Even if tandem mass spectrometers are good analytical tools to structurally characterize peptides and proteins, sequence analysis of cyclic peptides is often ambiguous due to the random ring opening of the peptides and subsequent generation of a set of linear precursor ions with the same m/z. Here we report combined use of chemical derivatization and multistage fragmentation capability of ion trap mass spectrometers to determine primary sequences of a series of closely related cyclic peptides.