to bring protein in soluble fraction - my protein is cysteine rich and i am getting it in insoluble fraction. (Aug/30/2010 )

my protein is cysteine rich and i am getting it in insoluble fraction. i have tried growing bacteria under low temperature conditions but the protein is still present in insoluble fraction. what should i do to bring them in soluble fraction???????????

Hola, You don´t say us what E. coli strain use for expression, but for improving cytoplasmic disulphide bridges any of Origami or Rosetta-gamy 2 are recommended because they are trxB and gor 522. if I were you I would choose any of Origami B except lacI, and i would try growing it at 25-30 ºC analyzing expression without and light induction 0->0.1 mM IPTG. Good luck