Antibody glycan remodeling strategies generate monoclonal antibodies with homogeneous glycoforms to improve therapeutic efficacy. CD BioGlyco is proficient at remodeling antibodies with G1 glycoforms according to our client's special needs.
Immunoglobulin G (IgG) is a glycoprotein composed of two heavy chains and two light chains. The heavy chains and light chains together constitute the antigen-binding fragment (Fab) and the crystallizable fragment (Fc). The conserved asparagine (Asp) of IgG is glycosylated at position 297 in the CH2 constant domain of the Fc region. Glycans are important players in Fc effector function and are flexible and highly dynamic in IgG. Glycans in the Fc region can be modified by glycosidases to enhance the interaction of Fc receptors with glycans. The specific glycoforms of IgG are related to the function of antibody molecules. For example, fully sialylated IgG glycans are associated with increased anti-inflammatory properties. Deletion of core fucose residues in Fc glycans significantly improves antibody binding to Fcγ receptor IIIa (FcγRIIIa) and antibody-dependent cellular cytotoxicity (ADCC) activity.
Glycosidase is an enzyme that catalyzes the hydrolysis of glycosidic bonds in complex sugars. Glycosidase is divided into exoglycosidases and endoglycosidases. Endoglycosidases generally have glycoform-specific activity and have been widely used in the study of human glycoproteins and glycoforms. EndoH is an endoglycosidase that specifically hydrolyzes high-mannose glycans and partially hybrid glycans. EndoD from Streptococcus pneumoniae cleaves the chitobiose core of N-glycans. EndoS, EndoS2, EndoSe, and EndoSd endoglycosidases from Streptococcus are highly specific for IgG. Therefore, EndoS and EndoS2 have become valuable tools for antibody research.
Fig.1 IgG glycan remodeling by endoglycosidase. (Sjögren, et al., 2020)
Because the specific glycoform of the glycan in the Fc region of IgG is related to the function of the antibody molecule. To obtain therapeutic antibodies with consistent and homogenous glycoforms for enhanced therapeutic efficacy, it is necessary to modify the Fc region glycans of IgG through Glycoengineering strategies. CD BioGlyco has developed an efficient and specific antibody glycan remodeling service. We provide clients with human IgG (including human IgG1, IgG2, and IgG4) carrying homogenous G1 glycoforms through IgG-specific endoglycosidase. Our workflow is as follows:
1) Trim Fc glycans to the innermost N-acetylglucosamine (GlcNAc) by IgG-specific endoglycosidases.
2) Glycosynthase catalyzes the reaction of pre-assembled G1 glycan oxazoline with core GlcNAc to generate antibodies with homologous G1 glycoforms.
Fig.2 Process of remodeling an antibody with G1 Glycoform. (CD BioGlyco)
CD BioGlyco is a leading service provider specializing in Antibody Glycoengineering research. We provide clients with high-quality antibody remodeling services. If you are interested in our services, please feel free to contact us for more details.
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