title: Capillary isoelectric focusing and sodium dodecyl sulfate-capillary gel electrophoresis of recombinant humanized monoclonal antibody HER2.
abstract: Capillary isoelectric focusing (cIEF) and IEF of recombinant humanized monoclonal antibody HER2 (rhuMAbHER2) show five charged isoforms with estimated pI values ranging from 8.6-9.1. The cIEF assay demonstrated good precision with relative standard deviations (R.S.D.) 0.7-3.7% and 0.4-4.2% for intra and interassay analysis, respectively. The method was linear for the area of the main peak over the concentration range 2-250 micrograms/ml with a Pearson correlation coefficient > 0.99. The limit of detection for the main peak was determined to be 2 ppm. With both sodium dodecyl sulfate-capillary gel electrophoresis (SDS-CGE) and SDS-polyacrylamide gel electrophoresis, the nonreduced rhuMAbHER2 migrated as a single major peak with minor peaks in the aggregate and clip regions. After reduction, the electropherogram and the slab gel showed the expected heavy chain and light chain fragments with minor peaks in the aggregate and clip regions. The SDS-CGE assay showed good precision with R.S.D. values of 0.1-7.8% and 0.1-8.1% for intra and interassay analysis, respectively. The Pearson correlation coefficient for the area of the main peak was > 0.99 demonstrating linearity for the concentration range 0.5-500 micrograms/ml. The limit of detection for intact rhuMAbHER2 was determined to be 0.5 ppm. The data presented demonstrates the feasibility of replacing the slab gel techniques with capillary electrophoresis in a quality control environment.
authors.affiliation: Department of Quality Control Clinical Development, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: G
authors.initials: G
authors.lastname: Hunt
authors.forename: K G
authors.initials: KG
authors.lastname: Moorhouse
authors.forename: A B
authors.initials: AB
authors.lastname: Chen
mesh_terms: D000911:Antibodies, Monoclonal / Q000032:analysis* / Q000276:immunology*; D019075:Electrophoresis, Capillary; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007525:Isoelectric Focusing; D007526:Isoelectric Point; D008623:Mercaptoethanol / Q000737:chemistry; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology*; D011994:Recombinant Proteins / Q000032:analysis / Q000276:immunology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D013696:Temperature
chemical_list: D000911:Antibodies, Monoclonal; D008623:Mercaptoethanol; D018719:Erb-b2 Receptor Tyrosine Kinases; D011994:Recombinant Proteins; D012967:Sodium Dodecyl Sulfate