Researchers at the McLellan Lab in Austin, Texas, are using llama antibodies to attack ‘spike proteins’ found on the surface of the SARS-CoV-2 virus. (Source: BBC Science Focus)
1. What is a spike protein and what is its function?
A spike protein is a protein that decorates the surface of a coronavirus. Its job is to attach that virus to a host cell by binding to a receptor (on the host cell’s surface). Once it is attached, it fuses the viral membrane with the host cell membrane so that the virus can enter into the host cell and begin the process of replication.
The spike protein is the main machine that the virus uses to enter into our cells. So, without the spike functioning properly on the surface of the virus, the virus is neutralized and is non-infectious.
2. Why should we focus on llamas?
Camelids, which is a family that includes camels, llamas, alpacas and a couple of other animals, produce this special class of small antibodies (proteins produced by the immune system to fight off harmful bacteria and viruses), which are sometimes called nanobodies.
Camelid antibodies are about half the size of the conventional antibodies that humans would produce, and because of that small size, they have enhanced stability and they are also capable of binding to small crevices or pockets that larger antibodies wouldn’t otherwise by able to bind to. (This is why llama antibodies can bind to the spike proteins on coronaviruses.)
Author: Seoyeon Stephanie Chung
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