In the production process of antibodies, different physical and chemical factors are prone to produce various post-translational modification (PTM) variants. These PTMs may cause changes in the physical and chemical properties of drug candidates. For example, the mutual reaction of the antibody Fc receptor affects the binding activity to the target antigen. The occurrence of some PTMs may even reduce the stability of the antibody and cause the unneeded immunogenicity in drug discovery. Therefore, in the course of antibody research, it is necessary to analyze these potential factors and rationally improve the gene and structure of the target molecules. Creative Biolabs has extensive research experience in oxidation analysis and can provide efficient and accurate testing and modification services.
Fig.1 Schematic diagram of met oxidation on antibody biological function. (Mo, 2016)
The common oxidation sites of candidate drugs, such as antibodies, are amino acid residues, including Met, tryptophan (Trp), cysteine (Cys), Lys and histidine (His). Among them, the Met residue has been considered as one of the most important oxidation sites in manufacturability assessment. Basing on the oxidation product types, we can provide a variety of customized technologies to evaluate their functions.
The susceptibility of Met residues is primarily dependent on where the solvent is exposed to the protein structure. Oxidation of antibodies may cause conformational changes in the protein, resulting in reduced stability, and oxidation of the complementarity determining regions (CDRs) may even affect the biological activity of candidate drugs. Scientists in Creative Biolabs has used H/D exchange mass spectrometry to study the effects of oxidation between Asp and Met on the structure of antibodies in the CDR regions of model drug molecules, and finally to assess changes in antibody-antigen binding activity.
Our oxidation assay has high resolution and accuracy and does not require complex sample preparation. They are especially suitable for PTM research of antibodies under non-denaturing conditions. Based on the principle that neonatal Fc receptor (FcRn) can specifically bind to mAb Fc region under acidic conditions, the immobilized FcRn was used as a stationary phase to separate mAb, and the maturation level of mAb was analyzed by native MS technique, which provides a very useful reference for the analysis of mAb PTM.
Creative Biolabs has the most authoritative testing strategies and tools to provide you with accurate oxidation analysis. If you want to know more details, please contact us and we will happy to help you.