Expression of toxic protein
urbig at biokemi.su.se
Tue Jan 27 02:58:07 EST 1998
In article <6a6iak$6pp$1 at usenet.kreonet.re.kr>, wsyang at bioneer.kaist.ac.kr
(Wan Seok Yang) wrote:
> my recombinant protein is large(>100kDa) and toxic.
> When I transformed the vector only ~20 colony appeared that's
> about 1/500 efficiency compared to parental vector.
> So I introduced LacI vector to host(BL21(DE3)) and much more
> colonies appeared. But after IPTG induction the cell die.
> Most manual emphasize down regulation of basal level however
> they don't comment cell death after IPTG induction.
> Can I get my recombinant protein?
> (when survived ~20 colonies were tested for induction some of them
> showed induction band but I can't believe they are active...)
Try the higher stringency host Bl21(DE3)pLysS or BL21(DE3)pLysE (for
highest stringency), available from Novagen or the helper phage carrying
the DE3 (available from Invitrogen- it's not in the catalogue!).
email: urbig at biokemi.su.se
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