Characterization of the Polytactic Form of N-glycans

Glycosylation of proteins helps to regulate the structure and biological activity of glycoproteins. In addition, complex glycans, the major N-glycans observed on mature glycoproteins, show considerable structural diversity, which includes salivation, focusing, polylactic structures, and haptic patterns. The asparagine-linked glycans (N-glycans) of glycoproteins naturally exhibit different tentacle patterns, such as bi-, tri-, and tetra-tentacle forms. The proportion of tentacle forms varies depending on the type of glycoprotein. The antennal forms of N-glycans of glycoproteins are the main factors affecting their structural heterogeneity. On the other hand, the antenna pattern of N-glycans inherently plays a key role in the regulation of protein function. Multi-tentacle N-glycans have also been previously recognized as essential for robust hematopoietic activity.

Fig.1 An N-glycan with a triantennary form. (Maki, et al., 2020)

Cell Surface Triantennary Type N-glycan Glycoengineering Service at CD BioGlyco

Triantennary-type N-glycans have an important role in mammals. At CD BioGlyco, we offer cell-surface triantennary N-glycans glycoengineering services.

• We will use chemoenzymatic synthesis to prepare sialylated triantennary-type N-glycans and affix them to produce neoglycoproteins. This will be performed in assays with lectins/antibodies, cultured cells, and animals to test the effect of their branching patterns on affinity. Overall, our service supports viewing the details of the N-glycan structure (branching) and is used to modulate ligand properties.
• At CD BioGlyco, we also offer to explore the functional regulation of proteins by the N-glycans reach pattern. For example, we offer the chemical synthesis (liquid phase condensation reaction) of an erythropoietin (EPO) glycoform with a three-tentacle salivary glycan. In vivo experiments using mice showed that the additional antenna element significantly increased hematopoietic activity. This also indicates that the antenna pattern of the N-glycan inherently plays a key role in the regulation of protein function.

Fig.2 We offer a service based on triantennary type N-glycans. (CD BioGlyco)

Publication

Paper Title: Chemical synthesis of an erythropoietin glycoform having a triantennary N-glycan: significant change of biological activity of glycoprotein by addition of a small molecular weight trisaccharide.

Technology: Preparation of triantennary N-glycans based on biantennary N-glycans and study of their production in animals

Journal: Journal of the American Chemical Society

Published: 2020

Results: To efficiently prepare a sialyl glycopeptide having a triantennary glycan, the authors have designed a procedure for the liquid-phase coupling of N²-Fmoc-N⁴-oligosaccharyl-L-asparagine (oligosaccharyl asparagine) and protected peptides. Several methods were used to prepare glycopeptides, including coupling of sugar amine with aspartic acid, chemoenzymatic transglycosylation, and stepwise SPPS. In the case of SPPS, we used Fmoc- or Boc-protected oligosaccharide asparagine as a building block. Finally, the authors measured the in vivo hematopoietic activity of synthesized EPO 10 having a triantennary sialyl glycan based on the hematocrit value of mice. Based on the data analysis (RP-HPLC, ESI-MS, SDS-PAGE) of the synthesized EPO, it was found that the triple-tentacled form of EPO at position 83 has a great influence on the in vivo activity of EPO i.e., the synthesized EPO exhibits better in vivo hematopoietic activity.

Fig.3 Representative antennary form of complex-type N-glycan. (Maki, et al., 2020)

Applications

• Glycoengineering services of triantennary-type N-glycans on the cell surface can be applied to explore the functional regulatory roles of glycoproteins in the animal body.
• In biomedicine, glycoengineering systems for triantennary N-glycans can be used for the development of biologically active drugs.
• The glycoengineering system for cell surface N-glycans can be used to help scientists further explore the interactions between various types of glycans and proteins.

Advantages

• We have a comprehensive N-glycan glycoengineering platform to help our clients produce N-glycans in a variety of structures in a fast, high-quality manner.
• Our professional research team provides most of the services about N-glycans for our clients.
• The services we provide enable our clients to explore the various functions of glycoproteins more easily.

CD BioGlyco has constructed a complete Cell Surface Glycoengineering of N-glycans platform and provides clients with various types of Cell Surface Glycoengineering Technologies. Our professional research team will provide clients with almost all the production of N-glycans, as well as structural and functional exploration. If you are interested in our services, please feel free to contact us.