[ccp4bb] Artic Express: problem with chaperone copurification

[Gloria Borgstahl]

We have had good luck with making a protein soluble using the Artic Express
bacterial cell line BUT we can't get rid of the chaperone that copurifies.
We have tried adding ATP, MgCl2 and potassium to lysate and extensive
washes and this releases a bit of the chaperone.  Has anyone solved this
problem?  We have heard of adding denatured proteins to the lysate to
confuse el chaperono.  Does this work?
Many thanks in advance for a advice, Gloria