As an important biotechnology drug, the emergence of monoclonal antibody drugs provides a brand new approach for the treatment of various diseases such as cancer, autoimmune diseases and viral infections. Glycosylation modification is an important factor affecting the biological characteristics of monoclonal antibody drug structure, function development and pharmacokinetics. The most obvious effect of protein glycosylation modification is that it can increase the stability and solubility of the protein. The research of glycosylation modification is very important for the development of safe and effective drugs.
Many endogenous proteins or exogenous recombinant proteins (such as therapeutic recombinant proteins or monoclonal antibodies) that affect cells, tissues, organs, and even life, almost all undergo protein glycosylation modification during the intracellular maturation process, and sugar The difference in the quality of base modification may affect the expression level, structure and function of related proteins. Glycosylation can protect proteins by hiding their binding sites with proteases. Some researchers have found that the steric protection of N-glycosylation on neighboring peptides is due to the formation of hydrogen bonds between glycosylation and hydrophilic amino acids. Glycosylation can also hinder the binding of proteases to antibodies, thereby increasing the stability of antibodies.
The rapid development of monoclonal antibody drugs and their increasing importance in the treatment of various diseases have put forward higher requirements for the development of monoclonal antibodies and drug safety. The glycosylation modification of monoclonal antibody drugs affects the stability, effectiveness and safety of monoclonal antibody drugs. Therefore, it is very important to establish an efficient, fast and reliable qualitative and quantitative analysis method for glycosylation modification to fully characterize its glycosylation modification. Meaning. Medicilon Bioanalysis Department can provide FDA/CFDA GLP-compliant macromolecular drug bioanalysis services to support the screening and development of protein drugs, antibody drugs, vaccines and biomarkers, as well as preclinical and clinical research.
According to the modified sites of glycosylation, glycosylation can be divided into N-position glycosylation and O-position glycosylation. N-position glycosylation is located in Asn-297. The N-acetylglucosamine in the oligosaccharide is linked to the amide nitrogen on the asparagine residue to modify the protein, starting from the endoplasmic reticulum and completing the Golgi apparatus; O-position glycosylation is caused by The N-acetylgalactose in the oligosaccharide is connected to the hydroxyl group on the serine or threonine residue to modify the protein, which is completed in the Golgi apparatus. Some researchers have also explored the effect of glycosylation modification on the stability of the fusion protein of cytotoxic T lymphocyte-associated antigen 4 antibody (CTLA4-Ig) .
Researchers applied a variety of glycosidase N-glycosidase F (PNGase F), endoglycosidase F2 (EndoF2), sialidase (neuraminidase) and O-glycosidase (O-glycosidase) to process the samples. Measure the changes in sample purity after different digestion times by size exclusion chromatography (SEC); use Differential Scanning Fluorescence (DSF) to determine the changes in the overall thermodynamic parameters of the sample; use Differential Scanning Calorimetry (DSC) to determine the thermodynamics of each structural domain of the sample Parameter changes; heating under 45 conditions, samples were taken at 0, 1, 3, 5, 7, 9, 11 and 12 weeks, and changes in sample purity were determined by SEC. Finally, through a variety of analytical methods, it is found that glycosylation is closely related to the stability of CTLA4-Ig.
Protein post-translational modification is an important part of the process of protein structure and function maturation. Among the many protein post-translational modifications, glycosylation is one of the most important and complex modifications, and it is also one of the key quality attributes for evaluating antibodies. The realization of monoclonal antibody drug functions is closely related to its glycosylation modification. Therefore, in the development of antibody drugs, we need to focus on the glycosylation modification of monoclonal antibody drugs.
 Study on the effect of glycosylation modification on the stability of recombinant CTLA4-Ig [J].