A Systematic Study of Acidic Peptides for b-Type Sequence Scrambling

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Atik A. E., Yalcin T.

JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY, cilt.22, sa.1, ss.38-48, 2011 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 22 Sayı: 1
  • Basım Tarihi: 2011
  • Doi Numarası: 10.1007/s13361-010-0018-3
  • Dergi Adı: JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.38-48
  • Anahtar Kelimeler: b-type sequence scrambling, Macrocyclization, Glutamic acid, Aspartic acid, Adjacent acidic residues, COLLISION-INDUCED DISSOCIATION, TANDEM MASS-SPECTROMETRY, GAS-PHASE ION, PROTONATED PEPTIDES, INFRARED-SPECTROSCOPY, B(5) IONS, FRAGMENTATION PATHWAYS, SPECTRA, CYCLIZATION, REARRANGEMENT
  • Acıbadem Mehmet Ali Aydınlar Üniversitesi Adresli: Hayır

Özet

A systematic study was carried out to examine the effects of acidic amino acid residues and the position of the acidic group on the cyclization of b ions. The study utilized the model C-terminal amidated peptides XAAAAAA, AXAAAAA, AAXAAAA, AAAXAAA, AAAAXAA, AAAAAXA, AAAAAAX, XXAAAAAA, AAXXAAAA, AAAAXXAA, and AAAAAAXX, where X is a glutamic acid (E) or aspartic acid (D) residue. The CID mass spectra of b (n) (where n = 7 and 8) ions derived from XAAAAAA, AAAXAAA, AAAAAAX and XXAAAAAA, AAXXAAAA, AAAAXXAA, and AAAAAAXX exhibited very similar fragmentation patterns for both the glutamic and the aspartic acid peptide series. The CID mass spectra of MH+ derived from model peptides presented substantial direct and non-direct sequence b ions. The results indicate that b ions produced from acidic peptides can also undergo head-to-tail cyclization, which is the reason for the formation of the non-direct sequence b ions. The b ion spectra derived from the peptides became more complex as the number of acidic residues in the peptides increased. Side chains of glutamic and aspartic acid did not inhibit the cyclization of the b ions. Substantial water elimination was observed in all CID spectra of b (7) and b (8) ions. Finally, the preferential cleavage of glutamic or aspartic acid residues from macrocyclic structures of b ions was also investigated under various collision energy conditions.