Interactions of thorium and cerium with adenine nucleotides.

The present study demonstrates an effect of the actinide, Thorium (Th), and the lanthanide, Cerium (Ce), on the non-enzymatic hydrolysis of adenine and guanine nucleotides. Thorium was found to be a more effective catalyst of the reaction than Cerium. Further, both the elements promoted the binding of Creatine kinase (CK) to Cibacron blue F3 GA, the substrate analogue of the enzyme, even in the absence of Mg2+, the physiological cofactor. These observations imply that toxic heavy metals can mimic the functional effects of the essential elements despite differences in their physicochemical properties.