GSH problem

Laura Moen lmoen at
Wed May 20 11:25:26 EST 1998

   Is your protein too large to fold correctly if you simply let the Sulfhydryls oxidize after
removing the DTT by dialysis?  I would try that.  I would also try the analog in case that works
better.  (I assume you have one all picked out - I don't know of any off-hand.) Alternatively, can
you change your construct to a His tag instead of the GST fusion and avoid the sulfhydryl problem
that way?  Good luck.  Laura

tmitch1 wrote:

> Hello.  I was wondering if anyone has used a glutathione analog in which the sulfhydral group
> is blocked to elude bound GST-fusion proteins from a GSH-Sepharose Chromatography Column
> (Pharmacia).  Reduced glutathione (GSH) is currently used, but it binds to our peptides
> via two disulfide bonds to two cysteines in our target peptide.  DTT removes the GSH, but it
> produces the target peptide with reduced cysteine residues.  We suspect that the cysteines
> form a native disulfide bond in the absence of GSH and DTT.  Any suggestions?  Thanks for your
> time.
> Tracy Mitchell
> Loyola University of Chicago
> tmitch1 at

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