title: Matrix-assisted laser desorption/ionization signal enhancement of peptides by picolinamidination of amino groups.
abstract: Picolinamidination of amino groups in peptides was carried out using ethyl picolinimidate tetrafluoroborate synthesized from picolinamide and triethyloxonium tetrafluoroborate. The N-terminal amino group as well as the epsilon-amino group of lysine were derivatized. The matrix-assisted laser desorption/ionization (MALDI) signal of a peptide was enhanced 20-35-fold upon picolinamidination depending on the number of amino groups derivatized. The signal enhancement effect is much higher than that of acetamidination or guanidination previously reported. Improved protein identification by mass mapping of the derivatized peptides was demonstrated.
authors.affiliation: Department of Chemistry, Seoul National University, Seoul, Korea 151-747.
authors.forename: Jong-Seo
authors.initials: JS
authors.lastname: Kim
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Hie-Joon
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry*; D008969:Molecular Sequence Data; D010449:Peptide Mapping / Q000379:methods*; D010455:Peptides / Q000737:chemistry*; D010848:Picolinic Acids / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020539:Sequence Analysis, Protein / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D000596:Amino Acids; D010455:Peptides; D010848:Picolinic Acids; C030614:picolinic acid