I would strongly argue against protein crystals (in most cases) being
solid state. Most of the surface of a molecule is actually solvated and
protein crystals as they are miss some of the typical properties of
"solid state". Although in some cases oligomerization occuring upon
protein crystallization indicates fairly strong interactions between
molecules, still the crystals are actually half liquid.
This is the main reason why many ligand exchange and activity studies
could be performed even in protein crystals.
Quite often (I think) protein crystallographers would actually like
their crystals to really behave like solids (stability, localization of
disordered regions, etc.)
no need for cryoprotection and it is hard to make them ...
Jan Dohnalek
IMC Prague
Jayashankar wrote:
Here we are dealing with two different state of chemistry,
solid state and solution state, If one of the minima in solid state
resembles
the biological state minimum, then there is a possiblw way to clearly
define
the biology and its significant interaction of that particular 'mer'
of a protein, other wise we end
up with pure physical interaction.
But my question is have we answered Wouldn't the high concentration in
the crystallization drop further favor dimerization? this part ...
S.Jayashankar
Research Student
Institute for Biophysical Chemistry
Hannover Medical School
Germany.
On Thu, Dec 11, 2008 at 5:53 PM, Phoebe Rice <pr...@uchicago.edu
<mailto:pr...@uchicago.edu>> wrote:
Mass action is on the crystal's side.
Two recent examples of proteins that are dimers by standard
solution assays, but form weak/transient/co-factor-dependent
tetramers to function, and those tetramers are seen in the
crystal. (There is good solution data to back up the
relevance of the tetramer in both cases).
Yuan P, Gupta K, Van Duyne GD. Tetrameric structure of a
serine integrase catalytic domain. Structure. 2008 Aug
6;16(8):1275-86.
Mouw KW, Rowland SJ, Gajjar MM, Boocock MR, Stark WM, Rice PA.
Architecture of a serine recombinase-DNA regulatory complex.
Mol Cell. 2008 Apr 25;30(2):145-55.
Phoebe
==========================================
---- Original message ----
>Date: Thu, 11 Dec 2008 10:09:33 -0600
>From: "Santarsiero, Bernard D." <b...@uic.edu <mailto:b...@uic.edu>>
>Subject: [SPAM:#] [ccp4bb] O/T: can a protein which dimerizes
in solution crystallize as a monomer?
>To: CCP4BB@JISCMAIL.AC.UK <mailto:CCP4BB@JISCMAIL.AC.UK>
>
>In parallel with the discussion around this off-CCP4-topic,
are they any
>good examples of the opposite case, where the protein is a
monomer in
>solution (as evident from light scattering, MW determination
through
>centrifugation, EPR, etc.) but crystallizes as a dimer or
higher multimer?
>
>Bernie Santarsiero
Phoebe A. Rice
Assoc. Prof., 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
RNA is really nifty
DNA is over fifty
We have put them
both in one book
Please do take a
really good look
http://www.rsc.org/shop/books/2008/9780854042722.asp
--
==============================================
Mr. Jan Dohnalek, Ph.D
Institute of Macromolecular Chemistry
Academy of Sciences of the Czech Republic
Laboratory of Structural Analysis of Molecules
Heyrovskeho nam. 2
16206 Prague 6
Tel: +420 296809390
Fax: +420 296809410
http://protein.awardspace.com/
==============================================
