Hi all,

I am struggling with a protein complex that is too soluble. I have reached about 20 mg/ml but I still observe very little precipitation (clear drops in 90-95% of the tested conditions). The proteins are expressed in insect cells and going to higher concentration is not easily achievable.
I have tried different buffer conditions (salt concentration and pH) and I am testing temperatures. I am at a loss with what to try next.
Do you think PTMs (phosphorylation, acetylation) might be causing this?
Any input on how to decrease solubility?

Thank you very much in advance,

Francesca