title: A study in glycation of a therapeutic recombinant humanized monoclonal antibody: where it is, how it got there, and how it affects charge-based behavior.
abstract: The glycated form of a basic recombinant humanized monoclonal antibody (rhuMAb) was separated and quantitated by boronate affinity chromatography using optimized shielding reagents. Characterization on the isolated glycated material by peptide mapping analysis, using liquid chromatography-mass spectrometry (LC-MS) and tandem mass spectrometry (MS/MS) sequencing techniques, identified eight reactive lysine primary amine sites. The glycation reaction extent was similar among the various reactive sites, ranging from approximately 1 to 12%, and a single histidine residue separated the most and least reactive sites. Boronate chromatography run in a linear gradient mode separated monoglycated rhuMAb from higher order glycated species and indicated that the majority ( approximately 90%) of glycated rhuMAb is monoglycated. Low-level glycation on a heavy chain lysine located within a complementarity-determining region (CDR) did not significantly affect binding activity in potency measurements. The glycated forms also behaved as slightly more acidic than the nonglycated antibody in charge-based separation techniques, observable by capillary isoelectric focusing (cIEF) and ion exchange chromatography (IEC). The boronate column has significantly increased retention of aggregated rhuMAb material under separation conditions optimized for the monomer form. Recombinant protein glycation initially occurred during production in mammalian cell culture, where feed sugar and protein concentrations contribute to the total overall glycation on this antibody product.
authors.affiliation: Analytical Development, Genentech, South San Francisco, CA 94080, USA. quan.cynthia@gene.com
authors.forename: Cynthia
authors.initials: C
authors.lastname: Quan
authors.forename: Emily
authors.initials: E
authors.lastname: Alcala
authors.forename: Irena
authors.initials: I
authors.lastname: Petkovska
authors.forename: Domenic
authors.initials: D
authors.lastname: Matthews
authors.forename: Eleanor
authors.initials: E
authors.lastname: Canova-Davis
authors.forename: Ron
authors.initials: R
authors.lastname: Taticek
authors.forename: Stacey
authors.initials: S
authors.lastname: Ma
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000302:isolation & purification; D001897:Boronic Acids; D016466:CHO Cells; D002846:Chromatography, Affinity / Q000379:methods; D002852:Chromatography, Ion Exchange; D002853:Chromatography, Liquid; D006224:Cricetinae; D003412:Cricetulus; D005690:Galactose / Q000737:chemistry; D005947:Glucose / Q000737:chemistry; D006031:Glycosylation; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry; D008958:Models, Molecular; D011994:Recombinant Proteins / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
chemical_list: D000911:Antibodies, Monoclonal; D001897:Boronic Acids; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D005947:Glucose; D005690:Galactose