I had a protein that loved pH 3 if it was holo (citrate, ammonium bromide, and PEG) or pH 4 when apo. Those were microbatch conditions rather than vapor diffusion. If there is no indication of gross structural changes you might consider different pH soak on your crystals rather than finding a new condition. Citrate-phosphate buffers are great for a broad range of pHs (2.2-8) and you don't have to worry as much about changing chemical environments.
Just an idea, Katherine On Mon, Nov 7, 2011 at 8:31 AM, Heping Zheng <[email protected]>wrote: > I remembered that people had crystallize a series of > streptavidin-2-iminobiotin structures at a low pH. If it might help, check > the following PDBIDs: > > 2RTD > 2RTE > 2RTI > 2RTK > 2RTL > > > > > Hi everyone > > > > I have a protein that is extraordinarily stable at PH=3.0 or even 2.0. > > > > I want to crystallize it in the low PH and compare the differences > > between the crystals in regular PH and low PH. > > > > I was wondering how people set up the boxes in low PH, as usual buffers > > are mostly less acidic. > > > > Regards > > > > Sam > > >
