soluble protein expression in E. coli and cytosolic disulfides????

[Torsten Boerchers]

krasel at wpxx02.toxi.uni-wuerzburg.de (Cornelius Krasel) wrote:
>ohannes1 at jeflin.tju.edu wrote:
>> One way  express some proteins so that they are soluble is to express
>> them from a vector that 
>> puts a leader sequence on them so that they are secreted into the
>> periplasmic space between the 
>> plasma membrane and the bacterial cell wall.  This is a more
>> reducing environment and avoids some 
>  ^^^^^^^^oxidizing: periplasmic proteins often have disulfid bonds
>  	whereas those occur very rarely in cytoplasmic proteins
>
>> folding related problems that can result in insolubility.
>
>--Cornelius.
>
>-- 
>/* Cornelius Krasel, U Wuerzburg, Dept. of Pharmacology, Versbacher Str. 9 */
>/* D-97078 Wuerzburg, Germany   email: phak004 at rzbox.uni-wuerzburg.de  SP3 */
>/* "Science is the game we play with God to find out what His rules are."  */

Cornelius and other netters:

You correctly state that disulfide bonds occur very rarely in 
cytoplasmic proteins.
Does anybody know whether they occur at all? We are just puzzled
by a protein of which we think it is cytosolic but on the other
hand have some hints that make us speculate it could have a
disulfide bridge. I found it hard, however, to find published
evidence for the existence of cytosolic cystines.
Can anybody help?
Thanks
Torsten
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                          Torsten Boerchers                            /
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