His-tagged protein and SDS-PAGE migration

[Thomas Seib]

In article
<Pine.OSF.3.96.980325220537.21753J-100000 at saul9.u.washington.edu>, James
Bassuk <bassuk at u.washington.edu> wrote:

> nonsense.  his-tag won't by itself cause nothing more than an increase
> in MW of 600.
> 
> but, being a recombinant protein, all kinds of screwy things can happen.
> your question is too general because every protein would have an
> emperical answer.
> 
> Jim Bassuk
> U Washington
> Seattle
> 
> 
> On Tue, 10 Mar 1998 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
> > 
> > 

It is NOT nonsense. I also experienced with several different proteins
that adding a his6-tag can cause the protein to migrate at a higher
molecular mass in SDS-PAGE. I estimate the difference to about 2-3
kDA.

Matthias Engel,
University of Saarland,
Homburg

-- 
Thomas Seib
Kantstr. 12
66292 Riegelsberg