Structure and sequence determination using fragmentation

2 Structure and Sequence Determination Using Fragmentation 8.2.2.1 Fragmentation of Peptides 

The fragmentation of peptides can also be obtained by FTICR instruments. Besides the most commonly used activation method, namely CID, the activation can alternatively be performed without gas by infrared multiphoton dissociation (IRMPD) and electron capture dissociation (ECD). These methods fragment peptide ions in the ICR cell by emitting a laser beam or electron beam, respectively. 

From a practical point of view, the fragments may be classified in either of two categories those derived from the cleavage of one or two bonds in the peptide chain and those that also undergo a cleavage of the amino acid lateral chain. The nomenclature suggested by 

High- and low-energy fragmentation spectra of methionine-enkephaline (sequence YGGFM). The notation used is described in the text. Reproduced (modified) from Bean M.F., Carr S.A., Thorne G.C., Reilly M.H. and Gaskell S.J., Anal. Chem., 63, 1473, 1991, with permission. 

Roepstorff and Fohlman [37] and later modified by Biemann [38] allows the labelling of the various fragments that are obtained. 

---