Table of Contents
International Journal of Proteomics
Volume 2012, Article ID 804036, 6 pages
http://dx.doi.org/10.1155/2012/804036
Research Article

Identification of Human Serum Peptides in Fourier Transform Ion Cyclotron Resonance Precision Profiles

1Department of Parasitology, Biomolecular Mass Spectrometry Unit, Leiden University Medical Center (LUMC), Albinusdreef 2, 2300 RC Leiden, The Netherlands
2Department of Surgery, Leiden University Medical Center (LUMC), Albinusdreef 2, 2300 RC Leiden, The Netherlands

Received 29 February 2012; Accepted 21 March 2012

Academic Editor: Qiangwei Xia

Copyright © 2012 Simone Nicolardi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The continuous efforts to find new prognostic or diagnostic biomarkers have stimulated the use of mass spectrometry (MS) profiles in a clinical setting. In the early days (about one decade ago), a single low-resolution mass spectrum derived from an individual’s body fluid was used for comparative studies. However, a peptide profile of a complex mixture is most informative when recorded on an ultrahigh resolution instrument such as a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. In this study we show the benefits of the ultrahigh resolving power and the high mass accuracy and precision provided by an FTICR mass spectrometer equipped with a 15-tesla magnet. The ultrahigh-resolution data not only allow assignment of fragment ions with high charge states (4+, 5+) but also enhance confidence of human serum peptide identifications from tandem MS experiments. This is exemplified with collision-induced dissociation (CID) and electron transfer dissociation (ETD) data of middle-down-sized endogenous or protein-breakdown peptides that are of interest in biomarker discovery studies.