Details on CNBr Cleavage

Bill Abrams wra at
Fri Feb 24 11:59:54 EST 1995

In article <01HNE85WRY2Q001Z6A at>, CTHOMPSON at ARSERRC.GOV wrote:

> Hello,
> I was wondering if anyone could direct me to the correct use of a 
> Cyanogen Bromide Activated Matix on Sepharose 4B (by Sigma) which is
> lactose and Dextran.  I would like to cleave collagen at its methionine
> sites but I don't know if I can hydrate the Sepheraose with solutions
> with a pH around 2.0.  Will the cyanogen bromide come off into solution at
> that pH?
> Craig

The cyanogen bromide activated matrix you refer to is for preparation of a
covalently bound protein (of your choice) to the matrix for affinity
chromatography applications and not for cleavage of methione residues in
proteins or peptides. You want to buy cyanogen bromide. It is best to
acquire it in relative small quantities so it is fresh. The crystals
should be clear. Usually you suspend your protein in 70% formic acid or
neat trifluoroacetic acid with a 100 fold molar excess of cyanogen bromide
in an anerobic atm for 24 hrs. Check out Deutscher's Guide to Protein
Purification, Methods in Enzymology, Vol 182, page 610 for reference.

Bill Abrams

Bill Abrams, Ph.D.
University of Pennsylvania
School of Dental Medicine
wra at

More information about the Methods mailing list