title: Differentiation of phosphorylated and unphosphorylated peptides by high-performance liquid chromatography-electrospray ionization-infrared multiphoton dissociation in a quadrupole ion trap.
abstract: Infrared multiphoton dissociation (IRMPD) in a quadrupole ion trap coupled to high-performance liquid chromatography allows the selective dissociation of phosphorylated peptides in mixtures following chromatographic separation. This method is shown to be effective for differentiation of phosphorylated peptides from unphosphorylated ones; only the abundances of the phosphorylated species are appreciably decreased following exposure to 125 ms of 10.6-microm radiation. This LC-IRMPD-MS strategy is demonstrated for a mock mixture of peptides and a tryptic digest of alphaS1-casein. The ability of this technique to differentiate peptides based on phosphorylation state is unaffected by whether the peptides are protonated or sodium-cationized.
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Crowe
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Brodbelt
mesh_terms: D000595:Amino Acid Sequence; D002364:Caseins / Q000737:chemistry / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007477:Ions / Q000737:chemistry*; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D010766:Phosphorylation; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014357:Trypsin / Q000378:metabolism
chemical_list: D002364:Caseins; D007477:Ions; D010455:Peptides; D014357:Trypsin