A comprehensive structural analysis on reference monoclonal antibody(IgG1) was conducted

which provides a reference for further in depth research of quality and future quality controling.Exactive plus EMR mass spectrometry was used to detect the precise molecular weight(MW) before and after PNGaseF digestion

then calculating the N glycan content.The MW of the reference antibody ranged from 148 285.0 to 149 020.8

which was 145 810.4 after PNGaseF digestion

and the N glycan content ranged from 1.67% to 2.15%.The WCID-cIEF results showed that the isoelectric point(pI) of the antibody ranged from 8.21 to 8.74

in which the pI of the main component was 8.61 and the relative content was 6143%.Then

the charge heterogeneity was detected by ion exchange chromatography.The contents for basic peak

acid peak and main peak were 4.1%

23.9% and 72.0%

respectively

which were consistent with the pI distribution by WCID-cIEF analysis.Furthermore

the glycopeptide distribution and the glycosylated sites were analyzed by peptide mapping before and after PNGaseF digestion

as well as the complementary determinant region(CDR) of the heavy and light chains

and the oxidation sites and oxidation ratio of methionine.The disulfide bonds were also analyzed by peptide mapping before and after antibody reduction.Finally

the glycation of the C-terminal of the antibody was detected.Results showed that there was no glycation occured in the C-terminal of the reference antibody.