title: Analysis of peptides and proteins affinity-bound to iron oxide nanoparticles by MALDI MS.
abstract: Iron oxide nanoparticles modified with oleate have been employed for the extraction of peptides and proteins from aqueous solution before matrix-assisted laser desorption/ionization (MALDI) mass spectrometric (MS) analysis. Adsorption of peptides and proteins onto the nanoparticles were mainly through electrostatic attraction and hydrophobic interaction. The analyte-adsorbed iron oxide nanoparticles could be efficiently collected from solution using a magnet. No elution step was needed. With this preconcentration strategy, the lowest detectable concentration of angiotensin I, insulin, and myoglobin in 500 microL of aqueous solution were 0.1 nM, 0.1 nM, and 10.0 nM, respectively. In addition, the nanoparticles could extract the analytes from solution with a high content of salt and surfactant, thus eliminating suppression effect during MALDI MS analysis. This method was successfully applied to concentrate the tryptic digest products of cytochrome c. In addition, the tryptic digestion of cytochrome c can be directly conducted on the iron oxide nanoparticles.
authors: Department of Chemistry, Tunghai University, Taichung, Taiwan. ychang@thu.edu.tw <ychang@thu.edu.tw>
authors: Sarah Y
authors: SY
authors: Chang
authors: Nan-Yan
authors: NY
authors: Zheng
authors: Chee-Shan
authors: CS
authors: Chen
authors: Cheng-Dah
authors: CD
authors: Chen
authors: Ying-Yi
authors: YY
authors: Chen
authors: C R Cris
authors: CR
authors: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D005290:Ferric Compounds / Q000737:chemistry*; D008969:Molecular Sequence Data; D036103:Nanotechnology / Q000379:methods; D019301:Oleic Acid / Q000737:chemistry; D010449:Peptide Mapping / Q000379:methods*; D010455:Peptides / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D005290:Ferric Compounds; D010455:Peptides; C000499:ferric oxide; D019301:Oleic Acid