GST-activity, binding buffer

[Maor Bar-Peled]

Dear Netters; I was wondering if someone has tried systematically to check whether 
the GST expressed in E.Coli (using the pGEX system) binds the GSH-column
under different buffers, detergents, salts etc conditions?. 
 i.e Does extraction in Hepes or 
tris buffer allow similar binding of the GST to the column compared with PBS? 
             Does the GST activity remain the same in Hepes or tris buffers as
in PBS?
Thanks in advanced, Maor Bar-Peled.