GST-fusion protein is insoluble.

Michael DiDonato michael.didonato at
Tue Dec 17 10:16:42 EST 1996

In article <Pine.SCO.3.95.961216144146.18075C-100000 at>,
lina at PUBMS.PKU.EDU.CN wrote:

> Dear Netters:
>   I am trying to express a gene from rice in E. coli, using the GST-fusion
> protein system, but perhaps due to its high Cys content (17 Cys out of a
> total of 131 a.a.), the expressed product is insoluble. How should I
> solublize and renature it without the loss of its affinity to the
> glutathione-agarose? 
>   Thanks for any help in advance.
>           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>           Li Na
>           Bldg 46, Room 1033
>           Peking University, Beijing, 100871
>           P.R.China
>           Tel. (010)62754249 (O)
>           ------------------------------------       

The GST references book which can be obtained from pharmacia biotech has
many references which deal with renaturation of GST fusion proteins.  An
alternate method would be to try and make the bacteria express a soluble
form of the fusion.  This has sometimes been accomplished by the
coexpression of bacterial thioredoxin or the chaperone GroEL (there should
also be many references on this method).

Good Luck.

Michael DiDonato
Department of Biochemistry Research
Hospital for Sick Children
Toronto, Ontario, Canada
michael.didonato at

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