Combining Mass Spectrometry and Peptide Arrays to Profile the Specificities of Histone Deacetylases

This paper introduces the use of mass spectrometry to analyze peptide arrays for applications in profiling enzyme specificity. The strategy is illustrated with arrays containing 361 acetylated peptides to profile the activities of several histone deacetylases (HDACs). The arrays reveal distinct substrates that are preferred by members of the HDAC family. This example is particularly relevant because the label-dependent assays now used for these enzymes constrain the range of substrates that can be assayed and can perturb the intrinsic activities of the enzymes.