His-tagged protein and SDS-PAGE migration

[Arnoud van Vliet]

Hi,

I don't know the system, but if it is a 6-His system, then it can run
a bit higher on SDS-PAGE. My 10 and 14 kDa proteins (low histidine
content) ran at 16 and 20 kDa, respectively. However, there are
exceptions to the rule, as a third protein I expressed (high histidine
content) ran at the expected MW.

So summarizing: yes, up to 6 kDa higher (consult the QiaExpress manual
from Qiagen).

Hope this helps
Arnoud


On Tue, 10 Mar 1998 13:33:45 GMT, ct133 at columbia.edu wrote:
>Hi,
>
>Does anybody know whether his-tagged protein expressed from pRSET
>vector (Invitrogen) can migrate aberrantly on SDS-PAGE? 
>
>Thanks,
>
>C. Tunyaplin