Biological mass spectrometry: a primer

Biological polymers undergo numerous significant and fascinating interactions, such as post-translational modifications, non-covalent associations and conformational changes. A valuable parameter for the characterization of a biopolymer is molecular weight, Modern methods of mass spectrometry, including electrospray ionization and matrix-assisted laser desorption ionization mass spectrometry, are ideally suited for the accurate determination of the molecular weight of a biopolymer of interest, Molecular weight measurements are now routinely utilized in the qualitative and quantitative analysis of macromolecules. In many cases small sample quantities (i.e. a few micrograms) limit the utility of nuclear magnetic resonance spectroscopy and X-ray crystallography in obtaining structural information. Thus, mass spectrometry offers an attractive alternative to the more traditional bioanalytical methods for rapid and sensitive measurements. The ultimate goal of these experiments is to obtain sufficient information in order to map the complex molecular circuitry which operates within the cell. In the analysis of complex mixtures mass spectrometry is even more powerful when utilized in conjunction with separation methods. Herein we present some of the aspects of modern biological mass spectrometry for the investigation of large molecules. For more advanced or detailed technical descriptions we refer the reader to a number of recently published reports.