Dear CC4BBers, I am trying to figure out what is the best way to determine the protein concentration of my membrane protein. My purified membrane protein is in 20mM Tris pH 7, 150mM NaCl and 0.02% DDM (CMC of DDM=0.0076%).
After reading the friendly manuals and searching online, I've learned that detergents interferes with assays like Bradford but can't find good descriptions of what works best. For now, I am trying to estimate concentration from absorbance at 280nm and using molar extinction coefficients based on aromatic amino acids, but again suspect detergent interference. I would like to know what other folks working on membrane proteins are doing. Thanks very much. Raji -- Raji Edayathumangalam Instructor in Neurology, Harvard Medical School Research Associate, Brigham and Women's Hospital Visiting Research Scholar, Brandeis University
