title: Peptide sequence information derived by pronase digestion and ammonium sulfate in-source decay matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
abstract: 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 Streptomyces 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.
authors.affiliation: Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Marzilli
authors.forename: T R
authors.initials: TR
authors.lastname: Golden
authors.forename: R J
authors.initials: RJ
authors.lastname: Cotter
authors.forename: A S
authors.initials: AS
authors.lastname: Woods
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000737:chemistry; D000595:Amino Acid Sequence; D000645:Ammonium Sulfate / Q000737:chemistry*; D001920:Bradykinin / Q000737:chemistry; D006868:Hydrolysis; D007202:Indicators and Reagents; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010455:Peptides / Q000032:analysis* / Q000737:chemistry; D011402:Pronase / Q000737:chemistry*; D012475:Salmonella / Q000737:chemistry; D017421:Sequence Analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D007202:Indicators and Reagents; D010446:Peptide Fragments; D010455:Peptides; D000324:Adrenocorticotropic Hormone; D011402:Pronase; D001920:Bradykinin; D000645:Ammonium Sulfate