Dear all, Sorry for this off-topic question.
I am studying a peripheral membrane protein (13kDa) by liquid state NMR, which is stable at pH 9.0 (50mM CHES pH9.0, 150mM NaCl and 1mM DTT). It crashes when I lower pH of buffer. The addition of 50mM Arg + Glu works to stabilize the protein at low pH, but interfere with the interaction between protein and phosphatidylinositol mono-phosphate (PtdInsP1). I've already tried some other ways to stabilize the protein, like high salt concentration (400mM), detergents (NP40 and Triton X-100). None of them worked. Any input would be very helpful. All the best, Ju
