title: Determination of Fab-hinge disulfide connectivity in structural isoforms of a recombinant human immunoglobulin G2 antibody.
abstract: The detection and characterization of unexpected disulfide-mediated structural variants of human immunoglobulin G2 (IgG2) antibodies was recently the subject of two copublications. In this paper, we present data to confirm the previously reported structures and elucidate the complete disulfide connectivity of each variant through the application of a novel analytical methodology. In this manner, the data illustrate the presence of at least five structural variants, including the classical structure with independent Fab domains and a hinge region. Multiple subvariants of the IgG2-A/B and IgG2-B structures are identified; these subvariants of each structure differ through the order of attachment of Fab peptides to the sequential hinge cysteines. Furthermore, the connectivity of a novel subvariant of IgG2-B containing an intrachain disulfide linkage in the lower hinge region is elucidated. The results presented in this paper reveal that the population of IgG2 disulfide structural variants is yet more complex than recently reported.
authors.affiliation: Analytical Sciences, Amgen, Inc., 4000 Nelson Road, Longmont, Colorado 80503, USA.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.forename: Adam G
authors.initials: AG
authors.lastname: Harder
authors.forename: Heather M
authors.initials: HM
authors.lastname: Connelly
authors.forename: Lorna L
authors.initials: LL
authors.lastname: Maheu
authors.forename: Steven L
authors.initials: SL
authors.lastname: Cockrill
mesh_terms: D000595:Amino Acid Sequence; D004220:Disulfides / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry*; D007074:Immunoglobulin G / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D010449:Peptide Mapping / Q000379:methods*; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D004220:Disulfides; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D020033:Protein Isoforms; D011994:Recombinant Proteins