Fusion Protein Expression Systems

Ian A. York iayork at panix.com
Fri Feb 14 17:04:44 EST 1997


In article <Pine.SOL.3.91.970214141628.8779A-100000 at isnet>,
Steve  <smiles at bgsm.edu> wrote:
>
>I'm working on trying to overexpress a membrane protein in a fusion 
>system. I've tried the maltose binding protein fusions and Intein 

Have you removed the transmembrane portion of your molecule?  I've never
tried it, but I assume that this would mess up the folding of the fusion
protein fairly seriously, probably leading to rapid degradation.

I've tried GST fusions (Pharmacia, isn't it?), maltose-binding protein
(New England Biolabs), and his-tagged fusions of various breeds.  The MBP
fusion gave the highest expression by a wide margin, but the fusion
protein didn't bind to the column any more (apparently a problem in
something like 25% of MBP fusions) so it was of little use to me.  Of the
others, the GST fusion was my favourite, but the difference was small.  I
can't say that I've done enough to make this anything more than anecdotal,
though.

There are lots of tips for ways you can increase expression and/or
stability of your fusion protein.  I *think* they're in the FAQ for this
group; if not, perhaps they should be ... at any rate, you should be able
to track them down in the archives.

Ian
-- 
      Ian York   (iayork at panix.com)  <http://www.panix.com/~iayork/>
      "-but as he was a York, I am rather inclined to suppose him a
       very respectable Man." -Jane Austen, The History of England



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