soluble protein expression in E. coli

[Charles A Miller]

ijiwaru at wheel.dcn.davis.ca.us wrote:
: In article <4dgton$iud at lyra.csx.cam.ac.uk>, sb at mole.bio.cam.ac.uk (Saverio
: Brogna (Genetics)) wrote:

: > Dear someone,
: > I have expressed e protein in E. coli with differents systems (His-tag, 
: > Glutation-transferase fusion and wild-type) but I can not get it soluble.
: > DO YOU KNOW HOW TO EXPRESS PROTEINS IN A WAY THAT SOME IS SOLUBLE?
: > 
: > Thanks
: > -- 
: > Saverio Brogna
: > University of Cambridge, Departement of Genetics
: > Downing Street, Cambridge, CB2 3EH, England (UK)
: > tel +44-223-333970, fax +44-223-333992

: Invitrogen touts their thioredoxin fusion protein expression system as the
: method of choice for proteins or protein domains with solubility
: problems.  A person I work with is trying the system out now, but no
: results to report.  You might try giving that one a try.  They claim that
: you can heat the bacteria to precipitate out many of the bacterial
: proteins and that the thioredoxin fusion partner will keep the protein of
: interest in solution as a method to partially purify your protein.  You
: might check out their web site (sorry, don't have the address on hand).

: Lyle Najita
: Plant Pathology
: University of California - Davis

: ps - no I don't get paid by Invitrogen.




In response to this:

Novagen also makes a thiofusion vector (pET32) that includes a His Tag as 
well. In addition they also have an E. coli strain that aids in folding 
for this system. Both systems are from Genetics Institute. Novagens vector
appears to be more recent than Invitrogens..

chuck

oravaxcm at world.std.com