Biemanns Nomenclature

Biemann further improved the nomenclature scheme by description of immonium and satellite ions [3]. 

At higher energies, fragmentation of the peptide molecule can also occur outside its backbone, that is, in the side chains. Ions formed in this way are termed satellite ions (Fig. 6.8). 

In some cases they may serve to differentiate between selected amino acids. In particular, they allow one to distinguish between leucine and isoleucine, which have identical molecular weights but yield different sateHite ions (Fig. 6.9). 

TABLE 6.1. List of the Most Important Immonium Ions 

Numbers in bold represent the most abundant peaks, those in italics peaks of lower intensity. 

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K. Biemann, Nomenclature for Peptide Fragment Ions. In Methods in Enzymology, Vol. 193, J. A. McCloskey (ed.), Elsevier Science and Technology, Orlando, FL, 1990, 886-888. 

Cyclic peptides are analyzed less frequently then the linear ones but their sequencing and nomenclature are much more complicated. There is no generally accepted nomenclature scheme but we describe here the one proposed by Ngoka and Gross [4]. It takes account of Roepstorff-Fohlmann s and Biemann s conventions but introduces amendments to address cyclic peptide fragmentation. 

Biemann K. (1990), Nomenclature for peptide fragments ions, Meth. Enzymol. 193, 886-887. 

Figure 6. Post source decay spectrum of N-terminal tryptic peptide, PIVQNIQGQMVHQAISPR, of HfV-1 p24 . a-, b-, and y"-dominant fiagment ions, defined according to the nomenclature of Biemann (1990), are shown, confirmhig the partial sequences (amino acids 1-7, and amino acids 10-18).fPis defined as a formylated prohne.

Biemann, K., 1990, Appendix 5. Nomenclature for peptide fragment ions (positive ions). Methods Enzymol. 193 886-887. 

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