Antibody Drug PTM Analysis: Oxidation and Deamidation

Antibody drugs are a class of drugs that treat diseases through artificially synthesized antibodies, such as monoclonal antibodies, artificially synthesized antibody fragments, immunotoxins, antibody drug conjugates, etc. Post-translational modifications (PTMs) refer to the chemical modification process of proteins during or after translation, which plays a key role in cell differentiation, protein degradation, signal transduction, and protein interactions. Oxidation and deamidation are two important post-translational modifications. Oxidation mainly affects amino acids containing sulfur in antibody drugs, such as cysteine, which change the structure and function of the antibody drugs, thereby affecting their therapeutic effects. Non-enzymatic deamidation of asparagine and glutamine residues in antibody drugs is also a common post-translational modification. Deamidation in antibody drugs may affect the structure, stability, folding and aggregation of proteins, thereby affecting the safety and effectiveness of antibody drugs, and has become a key quality attribute of antibody drugs.

 

How to determine post-translational modifications such as oxidation and deamidation in antibody drugs has also become an important step in the drug quality control process. For the oxidation modification of antibody drugs, it is usually detected by analytical techniques such as high-performance liquid chromatography (HPLC) and mass spectrometry (MS). By comparing the antibody drug samples before and after treatment, the change in the content of sulfur-containing amino acids is analyzed by HPLC and MS to determine the degree of oxidation. The analysis method of deamidation is similar. Deamidation reaction causes a decrease in the mass of amino acids, and MS can detect this mass change. LC-MS or LC-MS/MS has higher sensitivity and is the "gold standard" for detecting PTMs.

 

MtoZ Biolabs provides customers with drug quality research services that comply with global pharmaceutical regulations. Based on Thermo Fisher's Q ExactiveHF mass spectrometry platform, Orbitrap Fusion mass spectrometry platform, Orbitrap Fusion Lumos mass spectrometry platform combined with Nano-LC, we provide researchers with analysis services for oxidative modification of recombinant protein drugs and deamidation modification analysis, which can determine whether the recombinant protein sample has undergone oxidative modification and deamidation modification, and determine the amino acid site and quantity of modification. All you need to do is tell us your experimental purpose and send the samples, and we will be responsible for all subsequent projects, including protein extraction, protein proteolysis, enrichment of modified peptides, peptide separation, mass spectrometry analysis, mass spectrometry raw data analysis, and bioinformatics analysis. Free consultation is welcome.