Native PAGE and His-tagged, recombinant proteins

[Rift]

Hello all,
I was curious if anybody had experience with (or could theorize about) the effect of a His-tag on a protein run in a gradient Native PAGE gel, versus the un-tagged form. Some more details about the type of gel are that it is a clear Native gel, so no Coomassie has been added. Another factor is that this is a gradient gel, so proteins will separate according to size as each reaches its pore limit and establishes a running pattern. Any information on this is much appreciated!