title: Rapid detection of proteins in transgenic crops without protein reference standards by targeted proteomic mass spectrometry.
abstract: BACKGROUND
  Liquid chromatography coupled with tandem mass spectrometry is increasingly used for protein detection for transgenic crops research. Currently this is achieved with protein reference standards which may take a significant time or efforts to obtain and there is a need for rapid protein detection without protein reference standards.
  
  
  RESULTS
  A sensitive and specific method was developed to detect target proteins in transgenic maize leaf crude extract at concentrations as low as ∼30 ng mg(-1) dry leaf without the need of reference standards or any sample enrichment. A hybrid Q-TRAP mass spectrometer was used to monitor all potential tryptic peptides of the target proteins in both transgenic and non-transgenic samples. The multiple reaction monitoring-initiated detection and sequencing (MIDAS) approach was used for initial peptide/protein identification via Mascot database search. Further confirmation was achieved by direct comparison between transgenic and non-transgenic samples. Definitive confirmation was provided by running the same experiments of synthetic peptides or protein standards, if available.
  
  
  CONCLUSIONS
  A targeted proteomic mass spectrometry method using MIDAS approach is an ideal methodology for detection of new proteins in early stages of transgenic crop research and development when neither protein reference standards nor antibodies are available. © 2016 Society of Chemical Industry.
authors.affiliation: DuPont Pioneer Agricultural Biotechnology, 8325 Northwest 62nd Avenue, P.O. Box 7062, Johnston, Iowa, 50131, USA.
authors.forename: Lindsey J
authors.initials: LJ
authors.lastname: Schacherer
authors.affiliation: DuPont Pioneer Agricultural Biotechnology, 4010 Point Eden Way, Hayward, California, 94545, USA.
authors.forename: Weiping
authors.initials: W
authors.lastname: Xie
authors.affiliation: DuPont Pioneer Agricultural Biotechnology, 8325 Northwest 62nd Avenue, P.O. Box 7062, Johnston, Iowa, 50131, USA.
authors.forename: Michaela A
authors.initials: MA
authors.lastname: Owens
authors.affiliation: DuPont Pioneer Agricultural Biotechnology, 8325 Northwest 62nd Avenue, P.O. Box 7062, Johnston, Iowa, 50131, USA.
authors.forename: Clara
authors.initials: C
authors.lastname: Alarcon
authors.affiliation: DuPont Pioneer Agricultural Biotechnology, 8325 Northwest 62nd Avenue, P.O. Box 7062, Johnston, Iowa, 50131, USA.
authors.forename: Tiger X
authors.initials: TX
authors.lastname: Hu
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006801:Humans; D018515:Plant Leaves / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry*; D015202:Protein Engineering; D040901:Proteomics; D012016:Reference Values; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry; D003313:Zea mays / Q000737:chemistry*
chemical_list: D010940:Plant Proteins
keywords: MIDAS; mass spectrometry; protein detection; target proteomics; transgene analysis