Caution! Distinct glycosylation of SARS-CoV-2 RBD shed new light in its binding characteristics.

Globally, SARS-CoV-2 coronavirus has infected over 100 million individuals, caused millions of deaths, and dramatically impacted everyday life.

The coronavirus is an enveloped RNA virus whose membrane spike glycoprotein – particularly the receptor-binding domain (RBD) of its S1 subunit, mediates interaction with host cell ACE2 receptors in the human respiratory tract, facilitating cell entry. The RBD is consequently the primary target of neutralizing antibodies.

Previous studies suggest glycosylation is important in RBD binding to the receptor, either directly or through conformational stabilization. This makes detailed characterisation of RBD glycosylation critical to the generation of effective recombinant spike proteins – used for interaction research, diagnostic purposes and in vaccine development.

Because glycosylation profiles may differ markedly between different biotechnologically produced proteins and their natural forms, Gstöttner et al here perform an in-depth structural and functional characterization of RBDs expressed in two different cell lines.

Use of IonOpticks Aurora Series columns proved critical for the sensitivity required to separate peptides containing the glycosylation sites N331 and N343 of the RBD. Together with glycomics data, glycosylation profiles were indeed different between cell line origin, but functionally, RBDs from both showed similar binding affinity. This suggests RBD glycosylation is involved in conformational stabilization rather than binding affinity. Despite the valuable insights in glycosylation, this analytical approach can also be used to batch-to-batch comparison.

Read the full paper
Structural and Functional Characterization of SARS-CoV-2 RBD Domains Produced in Mammalian Cells.
Analytical Chemistry 2021 93 (17), 6839-6847 (4 May 2021). doi: https://doi.org/10.1021/acs.analchem.1c00893

Gstöttner C, Zhang T, Resemann A, Ruben S, Pengelley S, Suckau D, Welsink T, Wuhrer M, Domínguez-Vega E

Commentary by Andreia Almeida, PhD.

About the author
Andreia is an application scientist at IonOpticks playing a key role on the utilisation and development of next generation HPLC columns. Andreia has completed her PhD at Institute for Glycomics – Griffith University in Gold Coast with a strong focus on Glycomics & Glycoproteomics.