Native polyacrylamide gel question

[Zophonias O. Jonsson]

In article <3505A9DB.EDD at cornell.edu>, mtm5 at cornell.edu wrote:

> What is th pI of the protein if the protein is positively charged at the
> pH of your running buffers it will not migrate towards the (+)
> electrode. You can play around with the pH of the buffers to try to give
> the protein a negative charge.
> 

This is indeed the most likely explanation.  The pI of the protein must be
a bit lower than the pH of the gel running buffer for it to enter the
gel.  There are however other possible explanations.  One would be that
the protein is partially aggregated.  Aggregates are easily resolved on
SDS gels but not on native gels.

Zophonias

_____________________________________________________________________
Zophonias O. Jonsson
Institut fur Veterinarbiochemie               Tel: (41-1)-635-54-75
Universitat Zurich-Irchel                     Fax: (41-1)-635-68-16
Winterthurerstrasse 190
CH-8057 Zurich
Switzerland
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