Large-Scale Protein Mapping Using Infrequent Cleavage Reagents, LD TOF MS, and ES MS

Publisher Summary The most useful cleavage techniques are those that cleave at lower abundance amino acids (Met, Trp, Cys, and His). Of these four amino acids, useful chemical reagents are available for the first three. The cleavage of proteins at methionine using cyanogen bromide (CNBr) is the most commonly used protein cleavage method. However, cleavage using most of the reported protocols leads to artifactual chemical modifications which interfere with mapping by mass spectrometry. Many of these modifications are not detectable by other methods of analysis. The use of other chemical cleavage methods can also produce products that are not ideal for mass analysis. This chapter discusses several chemical cleavage methods and describes observations with CNBr cleavage of proteins in preparation for mass spectral analysis.