Identification and characterization of an IgG sequence variant with an 11 kDa heavy chain C-terminal extension using a combination of mass spectrometry and high-throughput sequencing analysis.

ABSTRACT: Protein primary structure is a potential critical quality attribute for biotherapeutics. Identifying and characterizing any sequence variants present is essential for product development. A sequence variant ~11 kDa larger than the expected IgG mass was observed by size-exclusion chromatography and two-dimensional liquid chromatography coupled with online mass spectrometry. Further characterization indicated that the 11 kDa was added to the heavy chain (HC) Fc domain. Despite the relatively large mass addition, only one unknown peptide was detected by peptide mapping. To decipher the sequence, the transcriptome of the manufacturing cell line was characterized by Illumina RNA-seq. Transcriptome reconstruction detected an aberrant fusion transcript, where the light chain (LC) constant domain

SUBMITTER: Harris C 

PROVIDER: S-EPMC6816433 | biostudies-literature | 2019 Nov-Dec

REPOSITORIES: biostudies-literature