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We've posted an updated version of @ScientistShrimp @sckales TMPRSS2 @biorxivpreprint with some new information about active enzyme concentration in the assay. We also show the camostat metabolite is almost as effective as camostat. #COVID19 https://www.biorxiv.org/content/10.1101/2020.06.23.167544v2
We've had lots of queries about our assay and have been sharing updates on active supplies of enzyme, ensuring others can replicate the assay. Getting some good fedback.
Here's the updated activity panel showing FOY activity. This is really important as camostat is in clinical trials, but getting some shade because of the poor PK/stability of camostat.
@FrankNoeBerlin has done some nice work on mechanism recently you should check out: https://twitter.com/FrankNoeBerlin/status/1285909534444224520?s=20
Our assay runs in 1536-well plates, with good assay stats, and runs over 60 minutes.
Note that we could NOT see bromhexine inhibition of TMPRSS2. This really bothered us and delayed our original preprint - we held off and ran full analytical characterization to show our bromhexine was the right molecule and 99.9% pure - but no inhibition.
The fact bromhexine is not inhibiting TMPRSS2 doesn't mean it can't work against COVID, and other recent literature in cell models supports our data. @__ice9 @FrankNoeBerlin @gstanchev https://www.biorxiv.org/content/10.1101/2020.07.25.221135v2
Finally, two protease panels were tested and we see strong pan-inhibition of trypsin-like serine proteases. The paper @JSheltzer tweeted about today adds to this, showing inhibition of other TMPRSS proteases. I agree with this conclusion : https://twitter.com/JSheltzer/status/1291386474890506241?s=20
Here is the @ReactionBiology protease panel data - very clear that camostat, nafamostat and gabexate (all being tested in trials) hit a lot of proteases:
Not sure if they made the biorxiv page, but full raw data from protease profiling are also added as supplementary to the submitting manuscript.
More science still to be done!
More science still to be done!
So there were some reproducibility challenges, but lots of great new science coming out on TMPRSS2 - see in particular to two papers cited in the thread above.
These inhibitors act against TMPRSS2, but a larger family of likely redundant proteases.
These inhibitors act against TMPRSS2, but a larger family of likely redundant proteases.
They don't have to be specific to be effective, and it may be that pan-inhibition is essential to anti-SARS-CoV-2 activity.
TMPRSS2 specificity may be highly undesirable!!!
TMPRSS2 specificity may be highly undesirable!!!
Note that assay details are also posted to our OpenData Portal and HTS data will follow:
https://opendata.ncats.nih.gov/covid19/assay?aid=8
https://opendata.ncats.nih.gov/covid19/assay?aid=8
