Automated N-glycopeptide identification using a combination of single- and tandem-MS
We describe Peptoonist, a program that can automatically identify the glycans (sugars) present at each N-glycosylation site of a protein. The input to Peptoonist is a series of mass spectra, both MS and MS/MS, obtained from a liquid chromatography (LC) run of purified glycopeptides. The program uses MS/MS to identify glycosylated peptides, and single-MS to identify the N-glycans present on each of these peptides, at least to the level of monosaccharide composition. We validate the program on an LC run of mouse zona pellucida proteins that had been intensively hand annotated by a human expert. Our program doubled the number of glycopeptide identifications, and also found several likely errors in the hand annotation. In addition, it automatically made most of the same glycan isomer identifications as the expert annotator.
Goldberg, D. ; Bern, M. W. ; Parry, S.; Sutton-Smith, M.; Panico, M.; Morris, H. R.; Dell, A. Automated N-glycopeptide identification using a combination of single- and tandem-MS. Journal of Proteome Research. 2007 October; 6 (10): 3995-4005.