GST fusion protein expression problem - (Oct/17/2007 )

Does anyone have experience with this?
I have tried to express my protein which is a glycosyltransferase fused with GST (pGEX 4T-1).And its MW is 43kd() It can be induced in 1ml LB, but can not be induced in a large scale (100ml LB). My bacteria strain is BL21 and my induction condition: 37 deg, 200RPM, 1mM IPTG, induction 12hr.
Can someone give me an idea how to solve this problem? Thanks

You mean you can get your proetin in small scale preparation but not in large one?
this is strange because usually if you can get in a small scale you can get it also in large scale.....but i noticed something you said you induce for 12 hours in 37 degree?
i think its too long usually 3 -4 hours in 37 degree is enough if you want longer period reduce the temperature of incubation.
may this help you