Sciencemadness Discussion Board

Sars corona virus 'spikes'

Panache - 19-8-2020 at 00:15

What would the molecular weight of these spikes approximately be...are they large quaternary ordered protein conglomerates.
Or can they described better in chemistry terms as in terms of functional groups...

Tsjerk - 19-8-2020 at 02:00

The spikes are trimers of the glycoprotein S. One of these S glycoproteins is 1273 AA, which makes the trimer about 400 kDa, so 400.000 g/mol

Metacelsus - 19-8-2020 at 04:51

Note that the S glycoprotein is processed by a protease into S1 and S2 subunits, so the "trimer" is really a trimer of heterodimers. Furthermore, it is heavily glycosylated (hence the name "glycoprotein"), and the exact molecular weight depends on the glycosylation pattern. A single S1 subunit, when glycosylated, is roughly 90 kDa. The S2 subunit is also glycosylated but I'm not sure how much the full molecular weight is.

See:
https://www.nature.com/articles/s41467-020-15562-9
https://www.sciencedirect.com/science/article/pii/S009286742...
https://science.sciencemag.org/content/369/6501/330

[Edited on 2020-8-19 by Metacelsus]

symboom - 19-8-2020 at 05:32

This makes me think of this
CRISPR enzyme programmed to kill viruses in human cells

https://news.harvard.edu/gazette/story/2019/10/researchers-c...

Metacelsus - 19-8-2020 at 11:24

Quote: Originally posted by symboom  
This makes me think of this
CRISPR enzyme programmed to kill viruses in human cells


Yeah, the original function of CRISPR is to kill viruses in bacterial cells, so it's not surprising that it can also do that in human cells.

However, for human treatments, you need to kill the virus in every cell (or else it will keep spreading). CRISPR delivery efficiencies aren't even close to good enough for this. If you're lucky you might kill 99% of the virus, but that 1% will come right back.

(The solution here would be embryo editing so every cell has the CRISPR system. But that's very unpopular and also the safety is dubious.)