At the beginning of its existence, Covid-19 acquired a capacity that would be decisive in its relationship with humans. The virus produced a seemingly small change in its genetic code. It was probably an unfortunate accident: a fragment of genetic information from another virus was confused with that of the coronavirus while both were infecting a bat.
However, instructions that altered a key part of the virus: its ear protein were included in this small piece of genome. This important protein studies the outside of the coronavirus and is the part that binds to the outside of the cells, helping the rest of the virus to sneak inside where it can replicate.
This change to the Covid-19 peak protein meant it could sequester an enzyme found in the human body called furin. This enzyme acts as a molecular scissor, normally cutting open hormones and growth factors to activate them. But when the furin breaks down part of the Covid-19 ear protein, which normally folds into a series of loops on the outside of the virus, it opens like a hinge.
“This exposes a new spike protein sequence,” says Yohei Yamauchi, a reader of viral cell biology at the University of Bristol, UK, who has been studying how this change may have led to Covid-19 to be more infectious in humans. “It’s one of the changes that makes this virus really different from the previous coronaviruses that caused Sars and Mers.”
This new mutation meant that Covid-19 could suddenly attach to an important molecule that is scattered on the outside of human respiratory cells called Neuropilin 1. This molecule helps transport material inside the cells. · Cells and deeper into the tissues; the mutation was like handing over the keys to Covid-19. to a new gateway to our cells and meant that the virus could replicate in greater numbers in human airways.
Although this mutation was only one of the short existence of Covid-19, it turned out to be important. Some researchers believe it may be one of the key mutations that allowed the coronavirus to skip species and begin to cause a disease that is spreading rapidly in humans. But almost as soon as he did this, he began to pick up other mutations.