For Research Use Only. Not for Clinical Use.

Creative Biolabs is a leading service provider that focuses on half-life extension for drug development. Based on our advanced platforms and extensive experience, now we can provide N-glycosylation half-life extension services for our clients all over the world.

Introduction of N-Glycosylation

In biochemistry research, N-glycosylation refers to the process that an oligosaccharide is attached to a nitrogen atom. In this process, the glycan is linked to the side chain of the Asn residue in the Asn-X-Ser/Thr consensus sequence via the glycosidase from GlcNAc, and X is any amino acid except Pro. There are mainly two types of bonds involved in glycoproteins, including bonds between sugar residues in glycans and bonds between glycan chains and protein molecules. In animal cells, almost all glycans attached to asparagine are N-acetylglucosamine (GlcNAc) in β-configuration.

N-glycosylation is one of the most complex post-translational modifications that influence the structural characteristics of therapeutic peptides and proteins thereby potentially modulating pharmacokinetics. According to the introduction of additional N-glycosylation via site-directed mutagenesis, the half-life of therapeutic peptides or proteins can be extended.

Fig 1. Types of N-glycans. The three different types (High Mannose, Complex and Hybrid) share a common core structure including the first two N-acetylglucosamine residues and the first three mannose residues. (Higel, 2016)

Applications of N-glycosylation for Half-Life Extension

It has been proved that the negatively charged sialic acids attached to the terminus of glycan chains play an important role in half-life extension for many glycoproteins with N-glycosylation. It is because the negatively charged properties of sialic acid are repelled by the negatively charged polysaccharides on the glomerular filter membrane, which slows down the renal clearance and the elimination rate.

Studies showed that hyperglycosylated, engineered erythropoietin (EPO) containing 5 amino acid changes (A30N, H32T, P87V, W88N, P90T) results in two additional N-glycosylation sites to increase sialic acid content. Compared with wild-type EPO, its half-life is 3.5 times longer. What's more, the introduction of three N-glycosylation sites into the GH sequence (3N-GH) increases the terminal half-life by 13-24 times in rats and the difference in multiples depends on the degree of sialylation. 3N-GH, which has a low degree of sialylation, exhibits significant pharmacodynamic effects in GH-deficient rats which means that sialic acid plays a key role in the properties of glycosylated GH.

Creative Biolabs has been a long-term expert in the field of drug development. As a pioneer and the undisrupted global leader in half-life extension, we offer a variety of solutions to improve your productivity and streamline your research processes. If you are interested in our products or services, please do not hesitate to contact us for more detailed information.

Reference

1. Higel, F.; et al. N-glycosylation heterogeneity and the influence on structure, function and pharmacokinetics of monoclonal antibodies and Fc fusion proteins. European Journal of Pharmaceutics and Biopharmaceutics. 2016, 100: 94-100.