[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[ccp4bb]: DLS: discrete dimer vs random assemlby
*** For details on how to be removed from this list visit the ***
*** CCP4 home page http://www.dl.ac.uk/CCP/CCP4/main.html ***
This is not CCP4-related, but there don't seem to be any
other active mailing lists or bbs's on other xtallographic
I'm running dynamic light scattering (DynaPro99) and am
wondering how to interpret what I'm looking at. If any
experts out there, I'd appreciate any input.
I have a protein where the active form and a previous
xtal form both are homo-dimers (45kDa monomer). Previous
xtal conditions were not screened for DLS. I observe
the protein as a sharp monomer DLS peak in the storage
buffer and as a BROAD DLS peak centered around 500kDa
in the previously successful xtallization conditions.
(This is the same protein that gave xtals, but 2 months
I can decrease the precipitant concentration to a point
where I find a slightly-less-broad DLS peak centered
around 100kDa... which _could_ correspond to the dimer...
or to the average MW of a random distribution of monmers
and small-ish agregates.
My thinking is that it's the small-ish aggregate option.
My thinking is that if it were the active dimer form,
the distribution would be just as sharp as the monomer
distribution in storage buffer.
I'm wondering if anyone has any rule of thumb about how
sharp a peak needs to be to call the solution homogenious?
donate free food www.thehungersite.com
diane h peapus, phd firstname.lastname@example.org
Chemistry & Chemical Biology +1-607-255-2174 (office)
Cornell University +1-607-255-2600 (graph room)
Ithaca, NY 14853 USA +1-607-255-1227 (fax)