title: Reliability and robustness of simultaneous absolute quantification of drug transporters, cytochrome P450 enzymes, and Udp-glucuronosyltransferases in human liver tissue by multiplexed MRM/selected reaction monitoring mode tandem mass spectrometry with nano-liquid chromatography.
abstract: Mass spectrometry (MS)-based multiplexed multiple reaction monitoring quantification of proteins has recently evolved as a versatile tool for accurate, absolute quantification of proteins. The purpose of this study was to examine the validity of the present method with regard to standard bioanalytical criteria for drug transporters, cytochrome P450 (CYP) enzymes and uridine 5'-diphospho-glucuronosyltransferases (UGTs). Membrane preparations from human liver tissue were used for target protein quantification. As a result, the determination coefficients (r(2)) of all targets were greater than 0.986. In the absence of matrix, inaccuracy values (expressed as % deviation) were -8.1% to 20.3%, whereas imprecision values (expressed as % coefficient of variation) were within 15.9%. In the presence of matrix, which consisted of digested plasma membrane fraction for transporters and digested microsomal membrane fraction for CYP enzymes and UGTs, respectively, the inaccuracy was -15.3%-8.1%, and the imprecision were within 18.9%. Sufficient sample stability of membrane fraction was shown for three freeze-thaw cycles, 32 days at -20°C, and in processed samples for 7 days at 10°C. In conclusion, this study demonstrated, for the first time, that the MS-based assay with nano-liquid chromatography provides adequate reliability and robustness for the quantification of selected drug transporters, P450 enzymes and UGTs.
authors.affiliation: Nippon Boehringer Ingelheim, Pharmacokinetics and Nonclinical Safety, Kobe, Hyogo 650-0047, Japan. sakamota@kaw.boehringer-ingelheim.com
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sakamoto
authors.forename: Takehisa
authors.initials: T
authors.lastname: Matsumaru
authors.forename: Naoki
authors.initials: N
authors.lastname: Ishiguro
authors.forename: Olaf
authors.initials: O
authors.lastname: Schaefer
authors.forename: Sumio
authors.initials: S
authors.lastname: Ohtsuki
authors.forename: Tae
authors.initials: T
authors.lastname: Inoue
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Kawakami
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Terasaki
mesh_terms: D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D002853:Chromatography, Liquid / Q000379:methods*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D014453:Glucuronosyltransferase / Q000378:metabolism*; D006801:Humans; D008862:Microsomes, Liver / Q000201:enzymology / Q000378:metabolism*; D036103:Nanotechnology; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D002352:Carrier Proteins; D003577:Cytochrome P-450 Enzyme System; D014453:Glucuronosyltransferase