title: Quantitative atlas of membrane transporter proteins: development and application of a highly sensitive simultaneous LC/MS/MS method combined with novel in-silico peptide selection criteria.
abstract: OBJECTIVE
  To develop an absolute quantification method for membrane proteins, and to construct a quantitative atlas of membrane transporter proteins in the blood-brain barrier, liver and kidney of mouse.
  
  
  METHODS
  Mouse tissues were digested with trypsin, and mixed with stable isotope labeled-peptide as a quantitative standard. The amounts of transporter proteins were simultaneously determined by liquid chromatography-tandem mass spectrometer (LC/MS/MS).
  
  
  RESULTS
  The target proteins were digested in-silico, and target peptides for analysis were chosen on the basis of the selection criteria. All of the peptides selected exhibited a detection limit of 10 fmol and linearity over at least two orders of magnitude in the calibration curve for LC/MS/MS analysis. The method was applied to obtain the expression levels of 34 transporters in liver, kidney and blood-brain barrier of mouse. The quantitative values of transporter proteins showed an excellent correlation with the values obtained with existing methods using antibodies or binding molecules.
  
  
  CONCLUSIONS
  A sensitive and simultaneous quantification method was developed for membrane proteins. By using this method, we constructed a quantitative atlas of membrane transporter proteins at the blood-brain barrier, liver and kidney in mouse. This technology is expected to have major implications for various fields of biomedical science.
authors.affiliation: Division of Membrane Transport and Drug Targeting, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Kamiie
authors.forename: Sumio
authors.initials: S
authors.lastname: Ohtsuki
authors.forename: Ryo
authors.initials: R
authors.lastname: Iwase
authors.forename: Ken
authors.initials: K
authors.lastname: Ohmine
authors.forename: Yuki
authors.initials: Y
authors.lastname: Katsukura
authors.forename: Kazunari
authors.initials: K
authors.lastname: Yanai
authors.forename: Yumi
authors.initials: Y
authors.lastname: Sekine
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Uchida
authors.forename: Shingo
authors.initials: S
authors.lastname: Ito
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Terasaki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001812:Blood-Brain Barrier; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D008297:Male; D026901:Membrane Transport Proteins / Q000032:analysis*; D051379:Mice; D008969:Molecular Sequence Data; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D026901:Membrane Transport Proteins