We present the use of Pronase digestion and in-source decay in the presence of ammonium sulfate as complementary techniques to confirm the amino acid sequence of a peptide. Pronase, a commercial preparation from Steptomyces griseus, is a combination of proteolytic enzymes. It produces carboxypeptidase and aminopeptidase ladders using a single Pronase digestion and represents an inexpensive, nonspecific, and fast supplement to traditional sequencing enzymes. However, N-terminal peptidase activity appears dependent on the terminal amino acid residue. We also introduce the use of saturated ammonium sulfate as an 'on-slide' sample additive to promote in-source fragmentation of peptides. Use of saturated ammonium sulfate resulted in a simple way to increase peptide backbone fragmentation and essentially produced either a cn or yn ion series. Together these techniques provide useful supplements to existing methods for peptide sequence information.
|Original language||English (US)|
|Number of pages||9|
|Journal||Journal of the American Society for Mass Spectrometry|
|State||Published - 2000|
ASJC Scopus subject areas
- Structural Biology