What should be done if the protein contains a tag in the middle of the sequence, i.e., not a terminal tag?
What should be done if the protein contains a tag in the middle of the sequence, i.e., not a terminal tag?
There is no reason that a 6xhis tag in the center of a protein would not work, as long as it is exposed after protein folding. In fact, some customers have successfully isolated proteins with a tag in this location. Even if the folding of the native protein masks the tag, it is possible that purification under denaturing conditions would work.