His-tag protein purification
plxigpg at pln1.life.nottingham.ac.uk
Tue Apr 30 10:57:41 EST 1996
I have another problem that needs sorted out:
I have been using Qiagens pQE system for the overexpression of a His
tagged protein. Basically I have PCRed a 1.2Kb fragment and transformed
XLI blue and SG(??)pREP4 (the strain they provide). I isolated 3
independant isolates 2 in SG and 1 in Xli - all were cloned into pQE32.
When I induced the cells I expected a 40KDa (ish) protein. However what
I did see was a 60KDa and a 40KDa. I then purified them under denatirung
conditions (6M urea) and both purified.
What could the 60KDa protein be? Do you get any read-thru the
terminators?? I think this is unlikely. The PCR fragments are of the
Thanks in advance
PS could you please email me direct as I have problems getting access to
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