title: Evaluation of phenylthiocarbamoyl-derivatized peptides by electrospray ionization mass spectrometry: selective isolation and analysis of modified multiply charged peptides for liquid chromatography-tandem mass spectrometry experiments.
abstract: Edman degradation in the gas phase has been observed by collision activated dissociation of N-terminal phenylthiocarbamoyl (PTC) protonated peptide to yield abundant complementary b₁ and y(n-1) ion pairs. Here, we demonstrated the relation between the observed losses of aniline and/or the entire PTC derivatizing group with the availability of mobile protons using electrospray ionization mass spectrometry. In order to select the peptides with more efficient fragmentation, while simplifying the mixture of peptides, we extend the phenylisotiocyanate (PITC) derivatization of amino groups to the selective isolation of multiply charged peptides (those having the number of arginines and histidines residues higher than one) using a procedure previously developed in our group. Thus, it was possible to identify in the filtered protein database the sequence of the isolated multiply charged peptides derived from a single protein and a complex mixture of proteins extracted from Escherichia coli using only the molecular mass and the N-terminal amino acid information. For this purpose, we developed a novel bioinformatic tool for automatic identification of peptides from liquid chromatography-tandem mass spectrometry (LC-MS/MS) experiments, which potentially can be used in high-throughput proteomics.
authors.affiliation: Proteomics Department, Center for Genetic Engineering and Biotechnology, P.O. Box 6162, Havana, Cuba.
authors.forename: Aniel
authors.initials: A
authors.lastname: Sanchez
authors.forename: Yasset
authors.initials: Y
authors.lastname: Perez-Riverol
authors.forename: Luis Javier
authors.initials: LJ
authors.lastname: González
authors.forename: Jesus
authors.initials: J
authors.lastname: Noda
authors.forename: Lazaro
authors.initials: L
authors.lastname: Betancourt
authors.forename: Yassel
authors.initials: Y
authors.lastname: Ramos
authors.forename: Jeovanis
authors.initials: J
authors.lastname: Gil
authors.forename: Roberto
authors.initials: R
authors.lastname: Vera
authors.forename: Gabriel
authors.initials: G
authors.lastname: Padrón
authors.forename: Vladimir
authors.initials: V
authors.lastname: Besada
mesh_terms: D000465:Algorithms; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid / Q000379:methods*; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D010670:Phenylthiourea / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013300:Streptokinase / Q000737:chemistry / Q000378:metabolism; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D010455:Peptides; D012710:Serum Albumin, Bovine; D010670:Phenylthiourea; D013300:Streptokinase