I probably it depends on whether you've got gunk or a functionally relevant oligomer in that void volume. Is it active?
RecA and Rad51 both form open-ended head-to-tail oligomers and yet they still crystallize.
=====================================
Phoebe A. Rice
Dept. of Biochemistry & Molecular Biology
The University of Chicago
phone 773 834 1723
http://bmb.bsd.uchicago.edu/Faculty_and_Research/01_Faculty/01_Faculty_Alphabetically.php?faculty_id=123
http://www.rsc.org/shop/books/2008/9780854042722.asp
---- Original message ----
>Date: Tue, 21 Feb 2012 18:21:03 -0500
>From: CCP4 bulletin board <[log in to unmask]> (on behalf of Raji Edayathumangalam <[log in to unmask]>)
>Subject: [ccp4bb] Aggregated protein for crystallization
>To: [log in to unmask]
>
> Hi Folks,
> As crazy as it sounds, if you have crystallized and
> managed to solve the structure of a protein from
> aggregated protein, please could you share your
> experience.
> After many constructs, many many expression schemes
> and after the usual rigmarole of optimization that
> is also often discussed on ccp4bb (buffers,
> glycerol, salt concentrations, pH, detergent,
> additives etc.), I now have a decently expressing
> truncated construct for my protein (80 kDa) that is
> pure but aggregated (elutes in the void volume from
> a Superdex200 column). I am tempted to make a
> boatload of aggregated protein and set up some
> crystal trays (after perhaps testing by CD). So I'd
> like to hear from folks who have been successful in
> solving structures from aggregates when many many
> known and tested optimization methods still leave
> one with aggregated protein.
> Thanks.
> Raji
> --
> Raji Edayathumangalam
> Instructor in Neurology, Harvard Medical School
> Research Associate, Brigham and Women's Hospital
> Visiting Research Scholar, Brandeis University
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