title: Identification of olive (Olea europaea) pulp proteins by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and nano-liquid chromatography tandem mass spectrometry.
abstract: Proteins in the pulp of olive ( Olea europaea ) constitute a minor fraction. They have been sparsely studied despite their suggested role in oil stability and olive allergenicity. The analysis of a pulp protein extract by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed a major band at 24 kDa that was subjected to tryptic in-gel digestion. Peptide extracts were analyzed by MALDI-TOF MS and nanoLC-MS/MS. The use of different search engines enabled the assignment of a number of fragmentation spectra to peptide sequences, identifying a major band as a thaumatin-like protein and other low-abundant proteins such a drought-induced protein SDi-6-like, an acyl carrier protein, Cu/Zn and Mn superoxide dismutases, a small heat shock protein, and an ATP-dependent protease subunit. Many of the produced spectra did not give good matches in the database searches, due to the scarce presence of O. europaea entries in protein databases. Nevertheless, a huge number of spectra corresponded to peptides, which showed a high degree of homology with others from sequenced organisms. These results proved that database searching with MS/MS spectra constitutes a promising approach for the characterization of olive pulp proteins.
authors: Department of Analytical Chemistry, Faculty of Chemistry, University of Alcalá, Ctra Madrid-Barcelona, Km 33.600, E-28871 Alcalá de Henares, Madrid, Spain.
authors: Clara
authors: C
authors: Esteve
authors: Benito
authors: B
authors: Cañas
authors: Estefanía
authors: E
authors: Moreno-Gordaliza
authors: Carmen
authors: C
authors: Del Río
authors: María Concepción
authors: MC
authors: García
authors: María Luisa
authors: ML
authors: Marina
mesh_terms: D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008969:Molecular Sequence Data; D031658:Olea / Q000737:chemistry* / Q000235:genetics; D010449:Peptide Mapping; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D010940:Plant Proteins