GST-fusion protein breakdown

[Cornelius Krasel]

marcvdc at lmb1.rug.ac.be wrote:
> Our GST-fusion protein is well expressed in E. coli and it is soluble, but it 
> runs about 8kDa lower than expected on PAGE. I fear we have breakdown of the 
> fusion. 
> 
> Does anyone know a solution for this problem ?

I am afraid there is no easy solution.

You may try:
- Changing of E. coli strain (to protease-negative strains, like BL21)
- Changing of time of induction (helps sometimes)
- Lowering of culture temperature (lowers protease activities)
- Inclusion of protease inhibitors when preparing the protein

Hope that helps,
--Cornelius.

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/* Cornelius Krasel, U Wuerzburg, Dept. of Pharmacology, Versbacher Str. 9 */
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