ZBiotech’s 100 Glycan Array helps researchers identify potential glycan ligands for the S1 protein of SADS-CoV.

Early evidence suggests N-linked glycoproteins are critical for SADS-CoV entry

In this recent study, researchers found that N-linked glycoproteins and host proteases are critical for the entry of swine acute diarrhea syndrome coronavirus (SADS-CoV) into cells. The study involved pretreating Vero and Huh-7 cells with tunicamycin, an inhibitor of N-linked glycosylation, followed by SADS-CoV infection. The results, measured using quantitative reverse transcription PCR (RT-qPCR) and immunofluorescence assays (IFA), demonstrated significant inhibition of viral replication, suggesting that N-linked glycoproteins are essential for SADS-CoV attachment and entry. Additionally, the study identified the involvement of various host proteases, including trypsin, cathepsin B, cathepsin L, and TMPRSSs, in facilitating viral entry. Trypsin was particularly effective in enhancing viral infectivity in Vero cells but had a limited effect on Huh-7 cells.

Glycan array results reveal complexity in viral entry mechanisms

The study proposed that N-linked glycoproteins might be entry ligands for SADS-CoV. However, the 100-glycan array analysis did not support this hypothesis. Researchers used the array to screen the binding interactions between the SADS-CoV S1 protein and various N-linked glycans. The results showed that the S1 protein did not bind to any of the 100 N-glycans tested, nor to common sialic acids Neu5Gc and Neu5Ac. This indicated that while N-linked glycosylation is crucial for SADS-CoV entry, the specific N-linked glycans involved remain unidentified. The array facilitated a comprehensive and high-throughput method to screen potential glycan interactions, significantly aiding the research by excluding common glycans as direct receptors for the virus.¹