From: Jo Butler <pjgb@mrc-lmb.cam.ac.uk>
  To  : Les Hicks <hicks@ualberta.ca>
  Date: Mon, 16 Jul 2001 10:08:33 +0100

Re: Differentiating between folded and unfolded states in sed vel

Dear Les,

This sounds like the old question, dating back to the days of undenatured 
electrophoresis.
The answer then was that, if the equilibrium was fast enough, one got a 
single peak running between the positions of the separate states.
Clearly, if the equilibrium rate is slower, the result will depend upon how 
rapid it is compared to the separation rate.

Jo

--On Friday, July 13, 2001 3:57 pm -0600 Les Hicks <hicks@ualberta.ca> 
wrote:

> Hi folks,
>
>     Here's a hypothetical question.  Say you have an approximately 7 kDa
> protein that is known from other techniques to undergo reversible folding
> / unfolding in phosphate buffer.  If the rate of folding / unfolding is
> fast (within the time course of a sed vel run, would it be possible to
> differentiate between the two states from the sed vel data?  I would think
> all you would see is a slightly broader boundary and that you would not be
> able to identify two individual boundaries for the two states.  Any takers
> on this question?  In any event, have a good week-end.
>
> Regards,
>
> Les Hicks
>
>



P.J.G. Butler,
MRC Laboratory of Molecular Biology,
Hills Road, Cambridge, CB2 2QH, UK.
Tel. +44 (0)1223 402296