Comparing mass spectrometric characteristics of peptides and peptoids—2†

Heerma, W., Boon, J.-P.J.L., Versluis, C., Kruijtzer, J.A.W., Hofmeyer, L.J.F. and Liskamp, R.M.J. (1997) Comparing mass spectrometric characteristics of peptides and peptoids—2†. Journal of Mass Spectrometry, 32(7), pp. 697-704. (doi: 10.1002/(SICI)1096-9888(199707)32:7<697::AID-JMS521>3.0.CO;2-U)

Abstract

The high-energy collision-induced dissociation (CID) spectra of the [M+H]+ and [M-H]- ions of substance P fragment 6–11, the retropeptide and the corresponding peptoid and retropeptoid were compared. The CID spectra of the [M+H]+ ion of the corresponding (retro)peptide and (retro)peptoid exhibit both B- and Y″-type sequence ions at identicalm/z-values. The differences in the relative abundances of these sequence ions, however, can be related to structural characteristics of the compounds. The fragmentation behaviour of theN-substituted immonium ions differs from that of the immonium ions derived from common amino acids by showing a preferential loss of a CH2=NH imine molecule. This dominant fragmentation reaction is suppressed in the CID spectrum of theN-substituted glutamine immonium ion in favour of a less energy demanding cyclization reaction involving the loss of NH3. The CID spectra of the [M-H]- ions of both peptides and peptoids show C-type ions, which appeared to be more abundant in the spectra of the peptides than in those of the peptoids.C-Terminal ″Z- and Y-type ions are characteristic of the peptides, whereas the peptoid spectra show relatively abundantN-terminal ″B-type ions. Both [M+H]+ and [M-H]- ion CID spectra show loss of amino acid-specific side-chains, which occurs as radical loss in the case of peptides and as molecular loss in peptoids.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Liskamp, Professor Robert
• Authors: Heerma, W., Boon, J.-P.J.L., Versluis, C., Kruijtzer, J.A.W., Hofmeyer, L.J.F., and Liskamp, R.M.J.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Journal of Mass Spectrometry
• ISSN: 1076-5174
• ISSN (Online): 1096-9888