Ellman's reagent will allow you to quantitate the number of free SH
groups; You should be able to find a method in Methods in Enzymology or
try the out of print book "Chemical Modification of Proteins" by Means and
Feeny
In article <4ibu6n$doi at studium.student.umu.se>, Michael Daws
<Michael.Daws at ucmp.umu.se> wrote:
> I have a 19-mer peptide (2200 MW) with a C-terminal cysteine which I
> purchased and received as a lyophilised powder. The company told me
> that the peptide would be greater than 95% monomer, however the results
> I have been getting would suggest that the majority of the peptide is
> disulphide bonded. Is there any nice easy colorimetric reagent I can
> use to detect free sulphydryl groups so that I can determine just how
> much of my peptide is disulphide bonded? Alternatively does anybody
> know a recipe for a gel that I could use to detect such a difference?
> Thanks.
>> Mike Daws
--
Thomas Chiles
Boston College
Biology Department
e-mail:ChilesT at hermes.bc.edu
