title: Development of novel guanidino-labelling derivatisation (GLaD) reagents for liquid chromatography/matrix-assisted laser desorption/ionisation analysis.
abstract: A new generation of guanidino-labelling (GLaD) reagents were developed for quantitative proteomics using offline microcapillary liquid chromatography (LC) matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS). In order to reduce the unwanted overlapping between the isotopic envelopes of the two differentially labelled peptide ions, a novel synthetic route was described for production of both (13)C- and (15)N-containing isotopomers of N,O-dimethylisourea. The use of these types of isotopes has no deleterious effect on the retention times of both differentially labelled peptides during offline microbore reversed-phase LC. In addition, the possibility to incorporate a mass difference of 4 Da can be exploited during post-source decay analysis to generate product ion spectra in which fragment ions containing the modifications appear as doublets in the corresponding product ion spectra, thus facilitating identification of the C-terminal fragment ions.
authors: Shimadzu Research Laboratory (Europe), Manchester, UK.
authors: Francesco L
authors: FL
authors: Brancia
authors: Jessica Z
authors: JZ
authors: Bereszczak
authors: Elzbieta
authors: E
authors: Piatkowska
authors: Daniela
authors: D
authors: Delneri
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D019791:Guanidine / Q000737:chemistry*; D007202:Indicators and Reagents / Q000737:chemistry*; D010449:Peptide Mapping / Q000379:methods*; D011506:Proteins / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013194:Staining and Labeling / Q000379:methods
chemical_list: D007202:Indicators and Reagents; D011506:Proteins; D019791:Guanidine