'Potential target for antiviral treatment for COVID-19 identified'

Researchers have identified a possible target for antiviral treatment for COVID-19 by assessing the overall mechanism by which the novel coronavirus enters host cells, and comparing it with the process seen in other similar viruses.

The researchers, including those from Cornell University in the US, compared the molecular sequence of small proteins involved in the fusion of the novel coronavirus SARS-CoV-2, and the SARS virus behind the 2002-03 epidemic, with the host cell membrane.

In the study, published in the journal Antiviral Research, they found that the virus that causes COVID-19, and the SARS virus had a 93 per cent similarity.

The scientists assessed the intricate procedure of membrane fusion in the viruses, which they said is a critical part of the mechanism by which coronaviruses spread.

 

Membrane fusion, they explained, is a multi-step process that begins with the virus recognising that it's found the right type of cell to infect.

To do this, the virus receives feedback from the chemical environment, including cues like the receptor that the host cell presents, the study noted.

The virus then attaches to the host cell receptor by way of the spike protein on its surface, it said.

According to the scientists, this process is followed by a piece of the spike protein, called the fusion peptide, interacting directly with the host cell membrane and facilitating merging to form a fusion pore, or opening.

They said the virus then transfers its genome into the host cell through this pore, and eventually hijacking the host cell's machinery to produce more viruses.

In the study, the research team found that charged atoms of calcium interacting with the fusion peptide can change the peptide's structure.

The study also assessed how the protein interacts with membranes in ways that promote infection in the other coronaviruses -- MERS and SARS.

In future studies, the researchers are hopeful of understanding how the virus moves into humans, what chemical cues facilitate the process, and why the virus is able to replicate so easily in the respiratory tract.