Hi Todd,
Do you mean reversible or irreversible dimers?
If the binding is reversible, then once crystal growth starts, Le
Chatelier's principle should take over, pull the equilibrium toward
monomer, and you should see minimal impact of dimer on your monomer
crystals. The same would be true in reverse for proteins that pack as
dimers or higher-order oligos in the crystal.
If the dimer formation is irreversible (ie. disulfide-mediated,
domain-swapped, ), they can be considered a chemically distinct entity
and could indeed disrupt crystal packing.
The most thorough treatment of the subject I know of is Chapter 8 of
McPherson, although I don't think it addresses dimers specifically, just
nonspecific aggregates. Perhaps still a place to start?
Shane Caldwell
McGill University
On Wed, Aug 13, 2014 at 5:40 PM, Todd Jason Green tgr...@uab.edu wrote:
Hello All-
I am interested in monomer/dimer contamination when building a crystal
lattice, ie. if you are building a crystal lattice with a monomeric species
of protein, incorporation of dimers may yield lattice or surface defects.
This species may be considered a macromolecular contaminant. I have read a
few papers on this subject, a couple are listed here:
I. Yoshizaki et al. / Journal of Crystal Growth 290 (2006) 185–191
Caylor CL1, Dobrianov I, Lemay SG, Kimmer C, Kriminski S, Finkelstein KD,
Zipfel W, Webb WW, Thomas BR, Chernov AA, Thorne RE. Proteins. 1999 Aug
15;36(3):270-81.
In each of the studies that I have read, lysozyme is the model protein for
these studies. I have not seen studies thus far that have been done with
other proteins. Can anyone point me toward other studies, specifically
non-lysozyme studies, where incorporation of two different oligomerization
states has been shown to yield crystals with higher level of defects?
Microscopy studies of such would be great too.
Thanks in advance-
Todd
