08 Feb 2021
Setting it Straight: Virus and vaccine - Part 1
What the SARS-CoV-2 shares with any other viral pathogen is that it’s bad news (for us) wrapped in a bit of protein and fat (lipid), with some sugars stuck here and there on the outside. We’ll forget the sugars for the rest of this, and the protein/lipid capsule/envelope is just there to protect the bad news – the 30,000 base pair RNA genome – as the virus particle (virion) makes its way passively from cell-to-cell, from person to person. One of the proteins it doesn’t have is myosin (the building blocks of muscle), and it has no ‘motor’ to move itself around. And, apart from those in the capsule that protect the RNA, the protein that concerns us most is the spike protein that sticks out from the surface of the virion and, via the receptor binding domain (RBD), sticks tightly to the ACE2 molecule on the surface of our cells. That high affinity receptor/ligand interaction triggers the entry of the whole virus particle into the cell, where it breaks apart to free its RNA information system and begin the process of reproducing itself.