Dear everybody,
I have crystallized a membrane protein at cold room temperature (4°C). The
protein was purified in 20mM Tris, pH8 with 1% bOG. The reservoir solution
contains 0.1M HEPES pH7.5, 0.05-0.2M (NH4)2SO4 and 15%-26% PEG400.
The cryoprotectant was made in such a way that all the other ingredients
remained the same except for the PEG400 increased to 35%. The crystal was
looped from the well and directly dipped into the cryo, however, the crystal
cracked within seconds of soaking. Speedy soaking and transferring of the
crytal into liquid N2 resulted 6Å diffraction in ESRF.
The crystal looked nice and I am wondering if this is just the problem of cryo.
Does anybody have experiences on this kind of membrane protein cryo-protect?
Any suggestions are highly appreciated!
Hubing
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