Structure based drug development is currently considered to be an important strategy for drug discovery. This strategy requires that critical knowledge of the three dimensional binding site on receptor molecules be known. NMR studies are frequently employed to ascertain important structural data on individual proteins as well as complexes of proteins with ligands. Deuterium labeled acids and bases are frequently used as buffers in deuterium oxide solutions for NMR studies on the structural conformations of bioactive molecules. Since pH is an important factor in any study of the conformational and stereochemical aspects of biologically active molecules, deuterated buffers are an essential part of the NMR experiments. However, the ionization constant for deuterium oxide (1.95 x 1015) is significantly different from that of water. Therefore, a pH comparison of deuterium-labeled acids and bases in deuterium oxide with nondeuterated aqueous acids and bases was conducted. Titration curve comparisons for deuterated and nondeuterated hydrochloric acid, acetic acid, sodium formate, and TRIS (tris[hydroxymethyl] amino methane) are described. Also, the average pKas of deuterated and non-deuterated acetic acid, formic acid, and TRIS are compared.
McConnell, Rose M.; Godwin, Walter E.; Stanley, Brant; and Green, M. Shane
"Acidity Studies of Deuterated Acids and Bases Commonly Used as Buffers in NMR Studies,"
Journal of the Arkansas Academy of Science: Vol. 51
, Article 21.
Available at: http://scholarworks.uark.edu/jaas/vol51/iss1/21