expressed protein is 5-6kda bigger than

[Christoph H. Winter]

Hi!

>Does anyone have such experience that expressed protein is 5-6kda bigger 
>that native one? my protein is 33kda and has additional 13aa + 6x His, 
>thus the expressed protein should 35-36kda, but I only got 40-42kda 
>expressed. Any explain? 

The ³Qiaexpressionist², the manual given with the Qiagen IMAC method,
describes the effect that proteins with a his-tag often run slightly
slower than they should (by calculation).

In our workgroup this was found as well!


Bye


Christoph                   

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< mailto:chw at sirius.mgen.uni-heidelberg.de >