Book Review

Michal Barski

Igor Kaltashov & Stephen Eyles:
Mass Spectrometry in Structural Biology and Biophysics: Architecture, Dynamics, and Interaction of Biomolecules.

Format: Kindle Edition
Size: 1436 KB
Sold by: Amazon Media EU S.à r.l.
Language: Englisch
Price: 136.00 EUR (hard­cover), 95.20 EUR (kindle edition)

Mass Effect

Mass spectrometry-based approaches to problems in structural biology are becoming more mainstream. This new research-oriented publication might provide a good opportunity to catch up on what mass spectrometry has to offer at your lab bench.

Ever heard of J. J. Thomson? As a natural scientist, you should have. A century ago, the Cambridge physicist discovered the electron, found the first evidence for isotopes of a stable element and invented the mass spectrometer. Thomson might be the most gifted teacher in scientific history, given the fact that seven (!) of his research assistants and even his own son won Nobel Prizes (as well as Thomson himself, of course, in 1906 for the, “great merits of his theoretical and experimental investigations”).

You see, the idea behind mass spectrometry (MS) isn’t new. Its application to large, high molecular weight biological molecules, however, only became possible with the development of the electrospray ionisation (ESI) technique in the 1980s. ESI allowed, for the first time, the gentle electrification and vaporisation of intact macromolecules. The discovery earned John Fenn and Masamichi Yamashita another Nobel Prize in 2002.

There has been a gradual increase in the popularity of MS across the life sciences, particularly in areas utilising protein characterisation and sequencing, i.e.: proteomics, protein expression and purification, as well as metabolomics. What forms the idea behind Kaltashov and Eyles’s book though, is a focus on the more specialised use of MS for studies on protein conformation, stability and interaction with other molecules. This is a unique approach among MS publications.

The father of mass spectrometry, J. J. Thomson, discovered and characterised the first elementary particle, the electron, in 1897, using an archaic-looking cathode ray tube.

As the book is directed at audiences stemming from both the “biological” as well as the more “technical” side of the topic, the first three (of nine) chapters introduce concepts of protein structure and thermodynamics, review the more well-established structural techniques such as X-ray crystallography, NMR and Circular Dichroism, and finally present the methodology of MS. This part of the book is, in your reviewer’s opinion, the weakest. It looks like the authors felt the need to include these chapters in their volume, but had little idea of how to do it. The pages are scattered with random pieces of information. Formulaic relationships between a certain set of parameters regarding each method feel out of context, with no further explanation or recurrent theme.

Random pieces of information

Another issue with this part of the book is the largely unexplained equations, which are also often somewhat detached from the main point of the chapter or paragraph. Readers (including myself) who do not come from a physical chemistry or engineering background have to do some outside reading to decipher terms like “periodic hyperbolic field configuration” or the formula for the Rayleigh ratio in Dynamic Light Scattering, which remain blissfully unexplained. It also must be added that the book contains neither a dictionary nor a list of abbreviations. A five-page index, in a 300-page book, does not make things any better.

The book definitely picks up in the second part. The finding that, under favourable conditions, protein conformation including the tertiary and quaternary structure, can be retained upon desorption from solution to the gas phase led to a wide range of techniques for describing the behaviour of protein assemblies. Many are presented here, including chemical cross-linking for mapping interactions in protein complexes and oligomers, stopped-flow unfolding/refolding observations and the mapping of solvent-accessible surfaces with hydrogen-deuterium exchange and chemical labelling.

Kaltashov and Eyles supplement their dense chapters with plenty of well-referenced experimental data and are not afraid of criticising certain weak spots in the MS approach to the study of protein conformation. Common discrepancies between the MS observations and an available crystal or NMR structure can mean that the native conformation of the protein might not be retained, but it unfolds and refolds to a different stable conformation over the course of the desorption/ionisation process.

Even bad experiments can give results

Overall, this will be an informative read for people familiar with MS. Unfortunately, as a stand-alone introduction to biological MS, or to the study of protein conformation this publication does not fulfil the norms by any standard. The organisation of the book, including the lack of cross-talk between figures, equations and the main body of the text, makes things even more complicated. Do not believe that it, “enables anyone not directly involved with the field to understand the important aspects and terminology” as is stated in the preface. However, as this is (to my knowledge) the only publication on this topic currently on the market, it will be of great importance to the more experienced biophysicist.

Letzte Änderungen: 25.03.2015