Expression of N-terminus fusion protein problem - (Apr/19/2005 )

I'm expressing a protein which is supposed to secrete in periplasm. I got it expressed and secreted OK. However, once I put a 15 residues peptide sequence on the N-terminus of this protein. I got very very low yield. The peptide sequence is very hydrophobic. I don't know if that's the problem.

Here is the construct:

promotor-signal peptide-15a.a. peptide-protein

Hope you guys can give me some suggestion.Thanks.

Hi,
Looking at your construct I think expressing your 15 residues peptide sequence on the N-terminu is blocking the signal for periplasm targeting of this protein, i would suggest expressing this peptide at the C-terminus. Good Luck!