Harsh, This article describes common buffers for CD on page 2: http://www.ncbi.nlm.nih.gov/pubmed/17406547 Or this article on page 8: http://www.ncbi.nlm.nih.gov/pubmed/16027053
It seems like phosphate is the best, because it has low absorption at 180-200nm region. From organic buffers Tris/H2SO4 seems to the the best. As I remember, Cl absorbs a lot in that UV region. Vitali On Wed, Mar 20, 2013 at 1:59 AM, Harsh Bansia <spideysp...@gmail.com> wrote: > Sorry for a simple and non-CCP4 question. > > I have determined the structures of three different mutants of a > thermostable protein by X-ray crystallography method. I feel that Mg2+ has > a role in protein stability. > > So I want to perform a thermal denaturation study by CD spectroscopy > both in presence and absence of Mg2+ ion. > > In this regards, what should be the suitable buffer for CD studies? May I > use PBS buffer ? Since phosphate sequester divalent cations like Mg2+. Is > it advisable to use PBS buffer. If so, what is maximum concentration of > Mg2+ ion that can be used say e.g. 5 mM? My protein was in Tris buffer and > lyophilized and have theoretical pI =4.56 and maximum activity at pH 8.4. > > > Thanking you in advances, > > harsh >
