... purchased were of the highest quality and purity. Acrylamide, EDTA, cAMP, dithiothreitol, phenyl-methanesulfonyl fluoride, and Tris were purchased from Sigma. N-Iodoacetylaminoethyl-1-naphthylamine-5-sulfo-nate ... protein from Escherichia coliMagdalena Tworzydło, Agnieszka Polit, Jan Mikołajczak and Zygmunt WasylewskiDepartment of Physical Biochemistry, Faculty of Biotechnology, Jagiellonian University, Krako´w, ... SJ, Hayashi F, Aiba H & Kyogoku Y (1990) A nuclear magnetic resonance study of the cyclicAMP receptor protein (CRP): assignments of the NHprotons of histidine and tryptophan residues and...