title: Characteristic mass spectral fragments of the organophosphorus agent FP-biotin and FP-biotinylated peptides from trypsin and bovine albumin (Tyr410).
abstract: A mass spectrometry-based method was developed for selective detection of FP-biotinylated peptides in complex mixtures. Mixtures of peptides, at the low-picomole level, were analyzed by liquid chromatography and positive ion, nanospray, triple quadrupole, linear ion trap mass spectrometry. Peptides were fragmented by collision-activated dissociation in the mass spectrometer. The free FP-biotin and peptides containing FP-biotinylated serine or FP-biotinylated tyrosine yielded characteristic fragment ions at 227, 312, and 329 m/z. FP-biotinylated serine yielded an additional characteristic fragment ion at 591 m/z. Chromatographic peaks containing FP-biotinylated peptides were indicated by these diagnostic ions. Data illustrating the selectivity of the approach are presented for tryptic digests of FP-biotinylated trypsin and FP-biotinylated serum albumin. A 16-residue peptide from bovine trypsin was biotinylated on the active site serine. A 3-residue peptide from bovine albumin, YTR, was biotinylated on Tyr410. This latter result confirms that the organophosphorus binding site of albumin is a tyrosine. This method can be used to search for new biomarkers of organophosphorus agent exposure.
authors.affiliation: University of Nebraska Medical Center, Eppley Institute, Omaha, NE 68198, USA. lmschopf@unmc.edu
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Schopfer
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Champion
authors.forename: Nate
authors.initials: N
authors.lastname: Tamblyn
authors.forename: Charles M
authors.initials: CM
authors.lastname: Thompson
authors.forename: Oksana
authors.initials: O
authors.lastname: Lockridge
mesh_terms: D000818:Animals; D001710:Biotin / Q000031:analogs & derivatives* / Q000737:chemistry; D002417:Cattle; D004781:Environmental Exposure / Q000032:analysis; D005397:Fish Venoms / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D009943:Organophosphorus Compounds / Q000032:analysis / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D014443:Tyrosine / Q000737:chemistry*
chemical_list: C403065:10-(fluoroethoxyphosphinyl)-N-(biotinamidopentyl)decanamide; D005397:Fish Venoms; D009943:Organophosphorus Compounds; D012710:Serum Albumin, Bovine; C004823:ryptisin; D014443:Tyrosine; D001710:Biotin