title: Improving de novo sequencing of peptides using a charged tag and C-terminal digestion.
abstract: An improved method for peptide de novo sequencing by MALDI mass spectrometry is presented. The method couples a charge derivatization reaction with C-terminal digestion to modify tryptic peptides. The charge derivatization attaches a fixed charge group onto the N-termini of peptides, and the enzymatic digestion after the derivatization step removes C-terminal basic amino acid residues such as arginine and lysine. The fragmentation of the modified peptide(s) under low-energy CID conditions (MALDI Q-TOF mass spectrometer) yields a simplified yet complete ion series of the peptide sequence. The validity of the method is demonstrated by the results from several model protein digests, where peptide sequences were correctly deduced either manually or through an automated sequencing program.
authors.affiliation: Life Sciences R and D, Waters Corporation, Milford, Massachusetts 01757, USA. Weibin_Chen@Waters.Com
authors.forename: Weibin
authors.initials: W
authors.lastname: Chen
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Lee
authors.forename: Henry
authors.initials: H
authors.lastname: Shion
authors.forename: Nicholas
authors.initials: N
authors.lastname: Ellor
authors.forename: John C
authors.initials: JC
authors.lastname: Gebler
mesh_terms: D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D012680:Sensitivity and Specificity; D020539:Sequence Analysis, Protein / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D010455:Peptides