Posttranslational modifications protocol

The composition of the lysis solution is dictated by the nature of the proteins under study and the subsequent techniques applied to the sample. One of the major choices to be made is whether or not a detergent is required at this stage. If the membrane and soluble fractions are to be separated the initial cell disruption protocol should not include a detergent, as many of the membrane proteins would be solubilized. In this case physical disruption of the cells should be used (e.g., sonication of cells or homogenization of tissues). The choice of lysis conditions is a vital consideration in this work, as proteins need to be solubilized while preservation of posttranslational modifications, inhibition of proteases, maintenance of protein-protein interactions, and, if an immunoaffinity purification step is to be performed, suitability for the antibody to function are essential. For example, SDS is very good at solubilizing membrane proteins but... 

Practical methodologies for peptide synthesis are the focus of this book. Thus not all reported methods could be described in length. The aim of this book is to provide laboratory protocols for both the specialist and the nonspecialist. The basic protocols provided here for solid-phase peptide synthesis are intended as a practical introduction to peptide synthesis, while the chapters on posttranslational and other modifications hopefully will also appeal to experienced peptide chemists. 

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