Chapter 14 - Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry for Lectin Analysis

Abstract

Since its inception in 1974, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has proven itself to be a valuable tool for the characterization of biomolecules. The employment of FT-ICR MS for biomolecular structural characterization offers several advantages, including high mass resolution, ultrahigh mass accuracy, and a wide mass range. FT-ICR MS is also an extremely versatile technique, and is capable of performing several varieties of tandem mass spectrometric methods. The most commonly used ionization technique combined with FT-ICR MS for biomolecule analysis is electrospray ionization (ESI). This chapter describes the key components of ESI FT-ICR MS instrumentation, along with the operating principles behind this technique. ESI FT-ICR MS allows for the accurate molecular weight determination of both peptides and proteins, thereby allowing for both a “bottom-up” and “top-down” approach to proteomics. FT-ICR MS offers several tandem mass spectrometric techniques which have been utilized for the characterization of lectins with ESI FT-ICR MS, including infrared multiphoton dissociation (IRMPD), electron capture dissociation (ECD), and electron detachment dissociation (EDD). In particular, ECD has been shown to be a powerful tool for biomolecular characterization, due to its retention of labile modifications and extensive peptide backbone fragmentation.