Resolving Disulfide Structural Isoforms of IgG2 Monoclonal Antibodies by Ion Mobility Mass Spectrometry

摘要

Recombinant monoclonal antibodies are an importantnclass of therapeutic agents that have found widespreadnuse for the treatment of many human diseases. Here, wenhave examined the utility of ion mobility mass spectrometryn(IMMS) for the rapid characterization of disulfidenvariants in intact IgG2 monoclonal antibodies. It is shownnthat IMMS reveals 2 to 3 gas-phase conformer populationsnfor IgG2s. In contrast, a single gas-phase conformer isnrevealed using IMMS for both an IgG1 antibody and a Cys-n232 f Ser mutant IgG2, both of which are homogeneousnwith respect to disulfide bonding. This provides strongnevidence that the observed IgG2 gas-phase conformersnare related to disulfide bond heterogeneity. Additionally,nIMMS analysis of redox enriched disulfide isoforms allowsnassignment of the mobility peaks to established disulfidenbonding patterns. These data clearly illustrate how IMMSncan be used to quickly provide information on the highernorder structure of antibody therapeutics.