Discovering the Coronavirus’s Achilles Heel

An international research team consisting of scientists at the Institute of Molecular Biotechnology (Austrian Academy of Sciences), the Johannes Kepler University Linz, BOKU (University of Natural Resources and Life Sciences Vienna), and the Karolinska Institutet in Sweden have conducted research on the coronavirus and discovered two proteins they describe as a “possible Achilles heel” when it comes to the virus’ contagiousness.

A Covid spike.
A Covid spike.

The findings were published in the EMBO Journal, opens an external URL in a new window and can potentially be use for cross-variant treatment.

Coronaviruses use a spike protein (S protein) to enter human cells. A team of researchers spearheaded by Josef Penninger (IMBA) has identified two sugar-binding proteins that hinder the viral entry of circulating SARS-CoV-2 variants.

In collaboration with Peter Hinterdorfer (Institute of Biophysics, Johannes Kepler University Linz), the research team used biophysical methods to explore exactly how this lectin binding takes place. The research has resulted in an impressive video recording of Covid's docking method.

Prof, Hinterdorfer remarked: "Lectins are so-called glycoproteins and in turn, they can bind to the antigens’ sugar molecule structure, such as the spike protein. These could inhabit neuralgic sites directly on the spike protein and keep the pathogen from binding to the cells. Picture this as blocking the door because the key is stuck."

The international team of researchers also discovered that the two lectins bind at a specific site, namely the N343 position on the S protein. This site on an infectious spike protein is so crucial that it cannot be unaccounted for. Additional research has shown that viruses containing a mutated N343 are not dangerous.

The team has another glimmer of hope to its credit: Experiments being conducted at the Karolinksa Institutet using human lung cells are showing that - under laboratory conditions - the two lectins are rendering the coronavirus less contagious.