- It is known that the coronavirus infects cells through its spike protein
- German scientists have recently gained more knowledge about this process
- One of their discoveries is that the entire protein is coated with sugar-like molecules that protect the spikes from antibodies
Early in the Covid-19 outbreak, Health24 wrote about the novel coronavirus and how it uses its spikes to dock onto the surface of human cells with the help of a receptor called ACE2.
Vaccine developers have centred their research around these spike proteins and ACE2 receptors, as it provided insight into how the virus triggers an immune response in humans.
According to a news release, German scientists – including experts from of the European Molecular Biology Laboratory (EMBL) in Heidelberg, the Max Planck Institute of Biophysics, the Paul-Ehrlich-Institut, and Goethe University Frankfurt – have been focusing on the surface structure of the virus to gain insights they can use for the development of vaccines and therapies to treat infected patients.
A flexible stalk
The team used a combination of cryo-electron tomography, subtomogram averaging and molecular dynamics simulations to analyse the exact molecular structure of the spike protein.
Their data showed that the globular portion of the spike protein, where the receptor-binding region is situated and helps the virus to successfully bind to human cells, is actually connected to a flexible stalk.
"The stalk was expected to be quite rigid," said Gerhard Hummer from the MPI of Biophysics and the Institute of Biophysics at Goethe University Frankfurt in a news release. "But in our computer models and in the actual images, we discovered that the stalks are extremely flexible.”
The researchers were able to identify that the stalk had three hinges that give it its flexibility.
"Like a balloon on a string, the spikes appear to move on the surface of the virus and thus are able to search for the receptor for docking to the target cell," explains Jacomine Krijnse Locker, group leader at the Paul-Ehrlich-Institut.
What does this mean for future vaccine development?
The new research didn’t only identify the flexibility of the spike protein, but also discovered that the entire protein, including the stalk, is coated with sugar-like molecules called glycans, which protect the spikes from antibodies.
This protective layer is an important discovery for vaccine and treatment development.
Image credit: Getty Images