Hi All, I am trying to design a 1D 31P pH titration experiment for a protein. I have been trying to identify a good buffer system that covers a broad pH range. The protein is very stable so I can push the pH beyond the pH 3.6-9 range that you get with acetate/Tris-acetate. I've been searching through the literature, but I can't seem to find an alternative to the Tris-acetate buffer system (though I may be making my google-fu too narrow). Is anyone aware of a different buffer system for pH titrations of protein samples? Thanks for your time. asked May 20 '14 at 10:20 K Sippel |
Do I understand you correctly that you're trying to find a single buffer system that spans a wide pH range? To do that, you'll definitely need to consider buffers with polyprotic acid components. However, why limit yourself to a single buffer composition? It's very common to screen the spectra of your protein in a wide variety of buffers to see which yield high quality spectra. As a starting point, take a look at this web page from the University of Buffalo: http://www.nmr2.buffalo.edu/nesg.wiki/Buffer_optimization There they give series of common buffers that span a large pH range. It's easy enough to buffer-exchange your protein and then record a quick spectrum. Since you're doing 31P NMR, simply exclude those buffers that contain phosphorous if you don't want to worry about extra signals appearing in your spectrum. good luck. answered Aug 22 '14 at 20:38 ChemMJW |