While preparing a recent review article in Mass Spectrometry Reviews on the analysis of post-translational modifications (PTMs) by mass spectrometry, we realized that, although there is much excellent work and many new tools being developed in this area, the field was lacking a coherent resource where these advances could be easily and readily accessed both by experts and those wishing to begin such studies. We subsequently decided that there was a need for a more comprehensive description of some of these modifications, and their analysis by mass spectrometry, in the form of a textbook. Since a detailed discussion of multiple modifications was required, it rapidly became apparent that this would require the support of experts in their own specialized fields. We are, therefore, grateful that a number of mass spectrometrists from around the world whom we, and others involved in proteomics, consider to be experts in the analysis of specific PTMs, agreed to contribute to this effort.
The aim of the book is to provide the reader with an understanding of the importance of the protein modifications under discussion in a biological context, and to yield insights into the analytical strategies, both in terms of sample preparation, chemistry, and analytical considerations required for the mass spectrometric determination of the presence, location, and function of selected important PTMs.
The scene is ably set with a concise introduction to the general strategies employed in PTM analysis by mass spectrometry, covering some of the key technologies which are referred to in more detail in subsequent chapters. Of course, well-known and more thoroughly investigated modifications such as phosphorylation, glycosylation, and acetylation are described in this work in great detail. However, other PTMs are garnering interest within the field and play major roles in protein function both in normal cellular regulation and in the disease setting. These PTMs are generally less well studied to date, and include, for example, tyrosine sulfation, glycation, nitration, and citrullina- tion - the conversion of arginine to citrulline. The analysis of ubiquitination and SUMOylation, both of which involve the addition of a second, small protein to the target in a complex regulation of protein localization, activity, and stability completes the array of modifications included in this book. In addition, the book rounds off with a description of one of the current “hot topics” in mass spectrometry: that of top-down studies of intact protein structure and modification, using the example of the characterization of monoclonal antibodies.
As editors, it has been our joint pleasure and privilege to have been given the opportunity to read at first hand these works and to compile them into a book of which we are very proud. On behalf of both of us we would like to express our sincere thanks and appreciation for the hard work and generosity given by all of the contributors.
Finally, to you the reader, we hope that you are able to use this book in your research, either as a reference book to dip into from time to time, to introduce you to new methodologies or new ideas to help support your work, or as a means of gaining a greater understanding of the analysis of PTMs by mass spectrometry from some expert scientists.
April 2016 John R. Griffiths
Richard D. Unwin Manchester, UK