Comparison of Peptide Ion Conformers Arising from Non-Helical and Helical Peptides Using Ion Mobility Spectrometry and Gas-Phase Hydrogen/Deuterium Exchange

Journal Article · Sat Dec 15 04:00:00 EST 2018 · Journal of the American Society for Mass Spectrometry

DOI:https://doi.org/10.1007/S13361-018-2053-4· OSTI ID:22922908

Karanji, Ahmad Kiani ^[1]; Khakinejad, Mahdiar; Kondalaji, Samaneh Ghassabi ^[2]; Majuta, Sandra N.; Attanayake, Kushani

---

1. West Virginia University, Department of Chemistry (United States)
2. Johns Hopkins University, Department of Biophysics (United States)

The dominant gas-phase conformer of [M+3H]{sup 3+} ions of the model peptide acetyl-PSSSSKSSSSKSSSSKSSSSK has been examined with ion mobility spectrometry (IMS), gas-phase hydrogen deuterium exchange (HDX), and mass spectrometry (MS) techniques. The [M+3H]{sup 3+} peptide ions are observed predominantly as a relatively compact conformer type. Upon subjecting these ions to electron transfer dissociation (ETD), the level of protection for each amino acid residue in the peptide sequence is assessed. The overall per-residue deuterium uptake is observed to be relatively more efficient for the neutral residues than for the model peptide acetyl-PAAAAKAAAAKAAAAKAAAAK. In comparison, the N-terminal and C-terminal regions of the serine peptide show greater relative protection compared with interior residues. Molecular dynamics (MD) simulations have been used to generate candidate structures for collision cross section and HDX reactivity matching. Hydrogen accessibility scoring (HAS) for select structural candidates from MD simulations has been used to suggest conformer types that could contribute to the observed HDX patterns. The results are discussed with respect to recent studies employing extensive MD simulations of gas-phase structure establishment of a peptide system. .

• OSTI ID: 22922908
• Journal Information: Journal of the American Society for Mass Spectrometry, Journal Name: Journal of the American Society for Mass Spectrometry Journal Issue: 12 Vol. 29; ISSN 1044-0305; ISSN JAMSEF
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
CROSS SECTIONS
DEUTERIUM
ELECTRON TRANSFER
HYDROGEN
ION MOBILITY
MASS SPECTROSCOPY
MOLECULAR DYNAMICS METHOD