Re: desalting

chris halkides (halkidesc@UNCWIL.EDU)
Fri, 05 Feb 1999 10:17:54 -0400

> Hi All,
> I am reducing and alkylating proteins in a guanidine solution and then
> buffer exchanging using the BioRad P6 centrifuge columns. Our group is
> looking for a faster, easier way to clean the sample (we can have many
> samples to desalt at a time). RP desalting doesn't work (protein
> precipitates and the protocol is WAY too long). I'm interested in some
> kind of desalting pipet that will make this a none-issue for the QC
> and Formulations folk. Are there any suggestions? The final solution
> should be in a neutral, enzyme-friendly, somewhat buffered solution.
> Thanks in advance for your help,
> Shawn Novick

I don't know whether I have a solution to offer or not. If your
protein is denatured in 6 M guanidinium and you remvove this, your protein
may aggregate if the protein concentration is too high. Can you use urea
to do the alkylation instead and then not remove the urea? Can you
tolerate dilution of the sample (this favors correct refolding)?

Hope this helps.

Chris Halkides

Christopher Halkides
Dept. of Chemistry, UNCW
601 S. College Road
Wilmington, NC 28403-3297
(910) 962-7427