title: Differential isotopic mass splitting as a mass spectrometric tool for identifying protease substrates.
abstract: A method is described whereby stable isotopic signatures were partially incorporated into both termini of a peptide sequence giving rise to a characteristic cluster of four peaks in the mass spectral analysis. Cleavage of this peptide by a protease between the labeled positions generates two fragments both displaying their own individual signature peaks. The event of protease cleavage of the peptide was monitored by the changes in clusters within the spectrum. We believe that this technique could be used to aid the discovery of new cleavage substrates for proteases. Additionally, the analysis can be automated with dedicated software designed to select and interpret the data since all peaks of interest contain predefined signatures and can be easily distinguished from background noise.
authors: GlaxoSmithKline Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, UK. SCM36093@gsk.com
authors: Stephen C
authors: SC
authors: McKeown
authors: Olivier
authors: O
authors: Heudi
authors: Corinne
authors: C
authors: Kay
authors: Peter
authors: P
authors: Marshall
mesh_terms: D002851:Chromatography, High Pressure Liquid; D007553:Isotope Labeling / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D015260:Neprilysin / Q000737:chemistry / Q000378:metabolism*; D010455:Peptides / Q000032:analysis / Q000378:metabolism*; D020539:Sequence Analysis, Protein; D012984:Software; D013379:Substrate Specificity; D014357:Trypsin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D010455:Peptides; D014357:Trypsin; D015260:Neprilysin