As I’ve mentioned in recent posts, our workhorse ACVR1 constructs have, for mysterious reasons, stopped expressing. This is clearly a massive problem, as with no protein we can not progress the project, and in the meantime, another DIPG patient has died, Aubreigh Nicholas, the 11-year-old girl who started the lemon face challenge. This is tragic, and exemplifies again the need for therapies against this cancer as soon as possible.
We’ve done a few 50 ml scale expressions with different viral levels and different virus amplifications in the past few weeks that have not worked at all. Last week Shubhashish Mukhopadhyay and Gavin Mckinley in our fantastic biotech team tried lowering the virus levels a lot – 4 x, 2 x and normal levels, on a 100 ml scale. Ellie Williams and I did parallel 50 ml purifications of these expression tests (documented here, in Zenodo), and they worked! We are so happy! Now we have to cross fingers that the expression will scale up to the litre scale again. I even got enough protein from this expression test to set up 5 plates with M4K3007, one of the compounds we are screening. There are no crystals in the 1-day images yet, but hopefully something will grow.
In the meantime, I will be on leave next week, but hopefully biotech will be able to grow up some protein for me next week or the week after, and I can get back to screening compounds and setting up trials for XChem fragment screening.
I’ll be back with news of the scale-up.