"Dr. Barry Panaretou" wrote:
>> We've tagged a protein with 6xHis, and expressed it in E.coli. It didn't
> bind nickel resin. We also tagged the C -terminus and again it didn't
> bond to nickel resin. Has anyone come across this before (protein is in
> supernatant after hard spin, so seems soluble--can also detrect with
> anti-his antobody on westerns, in both cases)
Sometimes tags get hidden inside the folded protein. Two options:
a) classical protein purification not relying on the tag
b) denature the protein to make the tag available
