(no subject)

[Vicky Cook]

Hello,
 
I am trying to produce TEV protease, and I have a few questions.  First,
why is DTT added to this enzyme?  I think it has to do with its being a
cysteine protease.  Second, I am observing strands or strings in my
dialysis bag, when I dialyze eluate from His bind column (in 20mM
Tris-HCl pH 7.9, 500mM NaCl, 1M imidazole) into STB (10mM Tris-HCl pH
8.0, 150mM NaCl, 1mM EDTA, 0.02% sod. azide, 5mM DTT).  I think it may
have to do with either the salt concentration or the DTT?  BTW, is it
imidizole or imidazole?  I have seen it written both ways.  I think they
are two different chemicals, but I am trained as a biologist, not too
good with chemistry....  :)
 
Thanks to all.