ENZYMATIC STUDIES OF THE EFFECT OF CU (II) ON OXYGEN RADICAL PRODUCTION STIMULATED BY DAUNORUBICIN AND AMETANTRONE

Daunorubicin can bind Cu (II) in Tris-HCl buffer (pH 7.4) and in the presence of NADH (100 μM). The complex is very stable. Cu (II) is not removed from the complex by cytochrome c reductase. The complexation of Cu (II) to daunorubicin gives rise to a modification of its redox properties. The complex, unlike the free drug, does not stimulate oxygen radical production. Ametantrone can also form a complex with Cu (II) in the conditions of enzymatic assays. Nevertheless, this complex is not stable in the presence of cytochrome c reductase. It dissociates immediately after the addition of the enzyme with releasing the metal ion. © 1990.