The biology activity of espressed protein - (Jul/02/2006 )

I have expressed the protein by pET32/BL21, but the biology activity is very weak, what should I do next?

thank you for your reply!

is it an eukaryotic protein?
yeast should be a better host...

Alot of people use Baculovirus and insect cells for mammalian proteins especially secreted/soluble ones.

thank you for your reply