these deuterium-dependent shifts have been previously ascribed to exchangeable protons on imidazole ligands [ nestor , l. , larrabee , j. a. , woolery , g. , reinhammar , b. , & spiro , t. g. ( 1984 ) biochemistry 23 , 1084 ] or to exchangeable protons on amide groups which are hydrogen bonded to the cysteine thiolate ligands ( a feature common to all blue copper proteins of known structure ) .
C0011744
deuterium
C0020275
hydrogen