title: Streamlining bottom-up protein identification based on selective ultraviolet photodissociation (UVPD) of chromophore-tagged histidine- and tyrosine-containing peptides.
abstract: We report a fast and highly efficient diazonium reaction that couples a nitroazobenzene chromophore to tyrosine and histidine residues, thus endowing peptides with high photoabsorption cross sections at 351 nm in the gas phase. Only the tagged peptides undergo ultraviolet photodissociation (UVPD) at 351 nm, as demonstrated for several Tyr- and His-containing peptides from protein digests. Additional selectivity is achieved by the integration of the UVPD-MS method with an in silico database search restricted to Tyr- and His-containing peptides. A modified MassMatrix algorithm condenses analysis by filtering the input database file to include Tyr/His-containing peptides only, thus reducing the search space and increasing confidence. In summary, derivatization of specific amino acid residues in conjunction with selective activation of the derivatized peptides provides a streamlined approach to shotgun proteomics.
authors.affiliation: Department of Chemistry, The University of Texas at Austin , 1 University Station A5300, Austin, Texas 78712, United States.
authors.forename: Julia R
authors.initials: JR
authors.lastname: Aponte
authors.forename: Lisa
authors.initials: L
authors.lastname: Vasicek
authors.forename: Jagannath
authors.initials: J
authors.lastname: Swaminathan
authors.forename: Hua
authors.initials: H
authors.lastname: Xu
authors.forename: Myong Chul
authors.initials: MC
authors.lastname: Koag
authors.forename: Seongmin
authors.initials: S
authors.lastname: Lee
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Brodbelt
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001391:Azo Compounds / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry*; D003979:Diazonium Compounds / Q000737:chemistry; D006639:Histidine / Q000737:chemistry*; D006801:Humans; D013058:Mass Spectrometry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009578:Nitrobenzenes / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D055668:Photochemical Processes; D011506:Proteins / Q000737:chemistry*; D014443:Tyrosine / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D003979:Diazonium Compounds; D009578:Nitrobenzenes; D010455:Peptides; D011506:Proteins; D014443:Tyrosine; D006639:Histidine; C036077:nitrobenzene; C009850:azobenzene