Three words: Maltose-Binding-Protein (E.coli is the most popular one)
Anything fused to this sucker will stay soluble as long as it is not cleaved
off. There is serious evidence that, in addition to promoting solubility of
the fusion protein, MBP also promotes actual folding of the fusion partner
(as long as MBP is upstream of the partner!).
Try it. pMAL is commercial - you might want to make sure that the linker
between your protein of interest and MBP is short (but not too short for
cleavage!).
Other fusion proteins are known to promote solubility, however they do not
seme to have the refolding bonus.
Other than that, try expression at lower temperatures, expressionin various
other types of cell lines, expression in insect cells, yeast, etc.
A.G.E.
"Guoping Su" <no at no.edu> wrote in message
news:a2iigd$7ce$1 at cronkite.cc.uga.edu...
> Hi, all,
>> I am looking for methods to improve solubility of a protein. I have the
gene
> built in a vector with his-tag on both terminals. but whenever I induce
the
> expression (in E.coli), the protein goes into inclusion body. Do you have
> better ideas to possibly get soluble protein?
> Thanks very much for your time.
