Problem GST-Fusion Protein in Ecoli

[Luc CAMOIN]

Hi,

I expressed a GST-fusion protein in Ecoli. The theoretical molecular weight
is 43 kDa. Western blot with anti-GST antibodies showed a band at 66 kDa.
Purification on Glutathione-sepharose-4B concentrate an unique band at 34
kDa. This 34 kDa band is not recognize with anti-GST antibodies.

I need some advice to explain these results. Is it known that a Ecoli
protein bind strongly to Glutathione affinity column? This 34 kDa is it a
protein or fragment related to my recombinant fusion protein?

I'am not familiar with these techniques so all advices will be welcome.

Thank you very much

Luc CAMOIN




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