Comparison of Trypsin Digestion pH for Peptide Mapping Workflows (TN-1270)

Peptide mapping is a common method for protein characterization The general workflow includes the isolation of a protein, followed by in solution digest using a serine protease to yield peptides, which are subsequently separated by LC and analyzed by UV and/or MS techniques Because of its specificity and the general size of peptides generated, trypsin is most commonly used Trypsin has an optimal activity at around pH 8 However, under even moderately basic conditions, deamidation can occur In this application note, we investigate the differences in digestion between a standard ammonium bicarbonate at pH 8 2 and a 1 X PBS, pH 7 4.