title: Capillary zone electrophoresis tandem mass spectrometry detects low concentration host cell impurities in monoclonal antibodies.
abstract: We have evaluated CZE-ESI-MS/MS for detection of trace amounts of host cell protein impurities in recombinant therapeutics. Compared to previously published procedures, we have optimized the buffer pH used in the formation of a pH junction to increase injection volume. We also prepared a 5-point calibration curve by spiking 12 standard proteins into a solution of a human mAb. A custom CZE-MS/MS system was used to analyze the tryptic digest of this mixture without depletion of the antibody. CZE generated a ∼70-min separation window (∼90-min total analysis duration) and ∼300-peak capacity. We also analyzed the sample using ultra-performance LC-MS/MS. CZE-MS/MS generated approximately five times higher base peak intensity and more peptide identifications for low-level spiked proteins. Both methods detected all proteins spiked at ∼100 ppm level with respect to the antibody.
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA.
authors.forename: Guijie
authors.initials: G
authors.lastname: Zhu
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA.
authors.forename: Liangliang
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Analytical Biotechnology, MedImmune, Gaithersburg, MD, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Heidbrink-Thompson
authors.affiliation: Department of Analytical Biotechnology, MedImmune, Gaithersburg, MD, USA.
authors.forename: Srilatha
authors.initials: S
authors.lastname: Kuntumalla
authors.affiliation: Department of Analytical Biotechnology, MedImmune, Gaithersburg, MD, USA.
authors.forename: Hung-yu
authors.initials: HY
authors.lastname: Lin
authors.affiliation: Department of Analytical Biotechnology, MedImmune, Gaithersburg, MD, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Larkin
authors.affiliation: Department of Analytical Biotechnology, MedImmune, Gaithersburg, MD, USA.
authors.forename: James B
authors.initials: JB
authors.lastname: McGivney
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA.
authors.forename: Norman J
authors.initials: NJ
authors.lastname: Dovichi
mesh_terms: D000911:Antibodies, Monoclonal / Q000032:analysis* / Q000737:chemistry*; D056148:Chromatography, Reverse-Phase / Q000379:methods; D004340:Drug Contamination / Q000517:prevention & control*; D019075:Electrophoresis, Capillary / Q000379:methods*; D004926:Escherichia coli; D006801:Humans; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000911:Antibodies, Monoclonal
keywords: Bottom-up proteomics; CZE; Host cell proteins