how to improve protein expression - (Oct/06/2008 )

Hi all,


I have recently cloned two inserts in one expression vector. According to the literature these two proteins form complex. So, we want to express them together.

I have tried 37, 18 degree with different IPTG and different time expression.

Untill now i dont see any overexpression band.

I have confirmed that IPTG is working well.

Dear Abijimmy,

Quick trouble shooting

• Do a quick western for the protein of interest to see the units are expressed or not.. If not
• I suggest check ur insert sequence thoroughly for any frameshifts or other sequence errors, make sure the frame is right.
• If you are expressing in E. coli, do a check for rare codons - if any use the right strain of expression host.

Thanks Aviprem,


I have already confirmed the sequence, frame. The expression host i am using has the compensation for rare codons.

I think the protein i intend to express are expressing and are inhibiting the growth of bacteria as the overnight colonies are very very tiny.

I am planning to use different expession strategy - use different vector or clone the two fragments seperately