title: Quantitation using enhanced signal tags: a technique for comparative proteomics.
abstract: Differential amidination of N-termini and lysine residues provides the basis for a novel approach to protein quantitation using MALDI mass spectrometry. Because the amidination of lysines increases their basicity and therefore MALDI ionization yields, the method is called quantitation using enhanced signal tags (QUEST). Amidine labels differ by methylene groups, leading to 14 Da mass differentials. The utility of QUEST is demonstrated while analyzing the digests of two model proteins using MALDI-TOF mass spectrometry.
authors.affiliation: Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Beardsley
authors.forename: James P
authors.initials: JP
authors.lastname: Reilly
mesh_terms: D000578:Amidines / Q000737:chemistry; D000818:Animals; D002845:Chromatography; D003574:Cytochrome c Group / Q000032:analysis / Q000737:chemistry; D006454:Hemoglobins / Q000032:analysis / Q000737:chemistry; D007477:Ions; D008239:Lysine / Q000737:chemistry; D008956:Models, Chemical; D010455:Peptides / Q000737:chemistry; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000032:analysis / Q000737:chemistry*; D020543:Proteome; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013997:Time Factors; D014357:Trypsin / Q000494:pharmacology
chemical_list: D000578:Amidines; D003574:Cytochrome c Group; D006454:Hemoglobins; D007477:Ions; D010455:Peptides; D011506:Proteins; D020543:Proteome; D014357:Trypsin; D008239:Lysine