Issue 9, 2014

IR action spectroscopy shows competitive oxazolone and diketopiperazine formation in peptides depends on peptide length and identity of terminal residue in the departing fragment

Abstract

The interplay between the entropically and enthalpically favored products of peptide fragmentation is probed using a combined experimental and theoretical approach. These b2 ion products can take either an oxazolone or diketopiperazine structure. Cleavage after the second amide bond is often a favorable process because the products are small ring structures that are particularly stable. These structures are structurally characterized by action IRMPD spectroscopy and semi-quantified using gas-phase hydrogen–deuterium exchange. The formation of the oxazolone and diketopiperazine has been thought to be largely governed by the identity of the first two residues at the N-terminus of the peptide. We show here that the length of the precursor peptide and identity of the third residue play a significant role in the formation of the diketopiperazine structure in peptides containing an N-terminal asparagine residue. This is additionally the first instance showing an N-terminal residue with an amide side chain can promote formation of the diketopiperazine b2 ion structure.

Graphical abstract: IR action spectroscopy shows competitive oxazolone and diketopiperazine formation in peptides depends on peptide length and identity of terminal residue in the departing fragment

Supplementary files

Article information

Article type
Paper
Submitted
10 Jan 2014
Accepted
26 Feb 2014
First published
26 Feb 2014

Analyst, 2014,139, 2137-2143

Author version available

IR action spectroscopy shows competitive oxazolone and diketopiperazine formation in peptides depends on peptide length and identity of terminal residue in the departing fragment

L. J. Morrison, J. Chamot-Rooke and V. H. Wysocki, Analyst, 2014, 139, 2137 DOI: 10.1039/C4AN00064A

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