Biomolecular Mass Spectrometry: Applications to Proteins and Peptides - Molecules: Nucleation, Aggregation and Crystallization - page 55

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Biomolecular Mass Spectrometry:
Applications to Proteins and Peptides

Leopold L. Ilag* and Gianluca Maddalo †

Mass spectrometry is an analytical technique which, as its name implies,
“weighs” molecules, and thereby can define molecular identity, interactions and
reactions. With this technique, molecules from a source are ionized (i.e. made to
carry a formal charge, either negative or positive) and subsequently enter the
mass analyzer where ions are separated according to their mass/charge ratio
( m / z ), and then a spectrum is recorded as ions reach the detector. Initially appli-
cations were limited to small molecules but nowadays even large macromolec-
ular complexes are amenable for analysis.

Keywords: Mass spectrometry; biomolecules; electrospray ionization (ESI);
matrix-assisted laser desorption ionization (MALDI); collision induced
dissociation/activation (CID/CAD); high molecular weight mass spectrometry;
molecular machines; proteomics; tandem mass spectrometry; imaging.

Introduction

The advent of soft ionization methods, namely, electrospray ionization
(ESI) and matrix-assisted laser desorption ionization (MALDI), revolu-
tionized the field of mass spectrometry (MS) particularly extending its
domain well into the life sciences. This made possible the ionization of
biological macromolecules, which are species too fragile for previous

*Corresponding author.
Department of Analytical Chemistry, Stockholm University, Stockholm, Sweden.
E-mail: [e-mail].
† Department of Analytical Chemistry, Stockholm University, Stockholm, Sweden.