This site has pI calculator and many other protein tools
Mitchell Isaacs wrote:
> "Michael Witty" <mw132 at mole.bio.cam.ac.uk> wrote in message
> news:Pine.SGI.3.96.1001231220504.14947613B-100000 at mole.bio.cam.ac.uk...> > Do we thing that theoretical pI's are good estimates? Is there a review
> > of theoretical versus experimentally determined pI's? Mike
> I don't know of any, but while the observed & theoretical pI's can vary
> rather enormously, it does give a good general idea. From my experience (not
> huge I'll admit) the majority of observed pI's fall within <1 unit of the
> theoretical pI.
>> If you're looking at a broad range (eg 4-7, 3-10) it can be quite helpful to
> know the theoretical pI.