Issue 16, 2016

Multiple gas-phase conformations of proline-containing peptides: is it always cis/trans isomerization?

Abstract

Ion mobility-mass spectrometry (IM-MS) is often employed to look at the secondary, tertiary, and quaternary structures of naked peptides and proteins in the gas-phase. Recently, it has offered a unique glimpse into proline-containing peptides and their cis/trans Xxx-Pro isomers. An experimental “signature” has been identified wherein a proline-containing peptide has its Pro residues substituted with another amino acid and the presence or absence of conformations in the IM-MS spectra is observed. Despite the high probability that one could attribute these conformations to cis/trans isomers, it is also possible that cis/trans isomers are not the cause of the additional conformations in proline-containing peptides. However, the experimental evidence of such a system has not been demonstrated or reported. Herein, we present the IM-MS analysis of Neuropeptide Y's wild-type (WT) signal sequence and Leu7Pro (L7P) mutant. Although comparison of arrival times and collision cross-sections of [M + 4H]4+ ions yields the cis/trans “signature”, molecular dynamics indicates that a cis-Pro7 is not very stable and that trans-Pro7 conformations of the same cross-section arise with equal frequency. We believe that this work further underscores the importance of theoretical calculations in IM-MS structural assignments.

Graphical abstract: Multiple gas-phase conformations of proline-containing peptides: is it always cis/trans isomerization?

Supplementary files

Article information

Article type
Communication
Submitted
09 رجب 1436
Accepted
07 شوال 1437
First published
07 شوال 1437

Analyst, 2016,141, 4863-4869

Author version available

Multiple gas-phase conformations of proline-containing peptides: is it always cis/trans isomerization?

C. B. Lietz, Z. Chen, C. Yun Son, X. Pang, Q. Cui and L. Li, Analyst, 2016, 141, 4863 DOI: 10.1039/C5AN00835B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements