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Flag tag not working, although theoretically it's there - (Jul/03/2008 )

The protein I work on has a flag tag at the N-terminus. I did a C-terminal deletion mutant of the protein. I checked the sequence and everything is correct: the N-terminus is identical to the original protein, the tag is there etc. The problem is that the tag is not recognized by a Flag antibody (checked 1 antibody and flag coIP beads). I really need it to work, I want to have both proteins (wt and deletion) tagged the same way for IP experiments. Any ideas why it doesn't work?

I would really appreciate your help!!!

thanks

j

-josephine-

QUOTE (josephine @ Jul 3 2008, 02:05 AM)
The protein I work on has a flag tag at the N-terminus. I did a C-terminal deletion mutant of the protein. I checked the sequence and everything is correct: the N-terminus is identical to the original protein, the tag is there etc. The problem is that the tag is not recognized by a Flag antibody (checked 1 antibody and flag coIP beads). I really need it to work, I want to have both proteins (wt and deletion) tagged the same way for IP experiments. Any ideas why it doesn't work?

I would really appreciate your help!!!

thanks

j


Perhaps the protein is folding differently and the flag tag is now getting buried so that it is not recognized by the antibody. Although, i would also make sure that it's being expressed. Do some RT-PCR to confirm. Perhaps by deleting some c-terminal sequences you also deleted regulatory sequences and its not being processed properly (either transcriptionally or translationally).

-smu2-