gel-shift problem

Sergey V. Orlov Serge at
Thu Oct 5 17:26:40 EST 1995

Eric Verdin wrote:
>The mobility of a DNA/protein complex in a gel shift is
>dependent on both the size of the bound protein and the charge
>of the protein.It is thus possible that your protein is bound
>to DNA but does not induce a shift because it is at its
>isoelectric point. To test this possibility, I would repeat
>the band shift using a buffer for the gel with a different pH.
>Good luck

Dear Eric,
the mobility of a DNA-protein complexes depend on DNA and protein(s).
If protein have Ip equal buffer pH, its electric properties don't have
influence to mobility of complexes, but mobility is provided by DNA, and
shape and size of protein will influence to it (because they determine
friction forces), thus retarded band will be formed. I hear about test
allowing investigate binding phosphorelated proteins with DNA. In this
test, phosphorelated proteins migrate to anode, while DNA-protein complexes
migrate to catode.

Sincerely, Serge Orlov,
e-mail: serge at

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