In our last class, we were talking about how viruses take advantage of repeated noncovalent interactions to become incredibly stable, making it very difficult to eradicate them from the body. This sounded perfectly horrible, so I thought I’d share an example of when this can actually be a great thing!
Foot-and-mouth disease (FMD) had a major outbreak among farm animals in the UK in 2001, creating huge loss in food production and major economic losses. So, farmers in the UK hoped to vaccinate their livestock to prevent future losses. However, existing vaccines are very unstable, resulting in limited shelf-lives and high expenses due to the need to use a cold-supply chain (they denature at room temperatures, and a ph<7.0).
So, researchers decided to actually alter the virus genome, changing the structure by one amino acid (one histidine was converted to a cysteine, creating a sulfide bond). This greatly improved the stability, and allowed them to (successfully) use the empty capsid of FMD as a vaccine in cattle.
So, sometimes virus’ incredibly stable structures can actually be used against them!
That’s really interesting that adding one disulfide bond can make such a big difference in stability. It also reminds me of scientists repurposed HIV’s capsid to use as a vector because of how efficiently it’s able to enter living cells.