[ccp4bb] effect of high salt on protein

Hi all, I keep my protein at 1 M NaCl, at some stage of purification, for about 30 minutes. Protein does not precipitate out at that stage and susequently when the salt concentration is reduced. I would like to know if such a high salt concentration can perturb ( irreversibly) the structure or

[ccp4bb] Protein-DNA complex for crystallization

Hi, I am trying to crystallize a protein-DNA complex. I purify the protein finally using gel filtration. I purchase single stranded complementary oligos (desalting from idtdna.com), mix them up and make DNA duplex by heating to 95 degree C and cooling to room temperature. I mix protein and DNA,

[ccp4bb] native PAGE for duplex DNA purification

Thanks to all those who replied to my query about purification of protein-DNA complex for crystallization. I figured out that extraction from native PAGE is the best way to purify duplex DNA. Does any one have a protocol that had worked for you. I found the following protocol that I am plannin

[ccp4bb] DNase inhibitors

Hi all, I have small crystals of protein DNA complex. I am worried about the possibility of presence of some DNases in the drop (I use DNase in the lysis buffer). I have Tris and MgCl2 in the crystallization condition, which makes me hesitant to use DEPC or EDTA/EGTA respectively. Are there an

Re: [ccp4bb] Off Topic:crystallization in the presence of glycerol

I have crystallized a refolded membrane protein in presence of Glycerol. It did not seem to affect crystallizability and speed of crystallization. If you have no luck in presence of glycerol, try to lower the glycerol concentration without compromising on the stability of the protein (buffer e