INACTIVATION OF CYTOCHROME-C-OXIDASE ACTIVITY IN MITOCHONDRIAL-MEMBRANES DURING REDOX CYCLING OF DOXORUBICIN

被引:33
作者
DEMANT, EJF
机构
[1] Department of Biochemistry C, Panum Institute, University of Copenhagen, DK-2200 Copenhagen N
关键词
D O I
10.1016/0006-2952(91)90626-G
中图分类号
R9 [药学];
学科分类号
1007 ;
摘要
Interactions of doxorubicin (DX) with the cardiolipin-dependent cytochrome c oxidase have been examined by using pig heart submitochondrial particles (SMP). A progressive and irreversible loss of oxidase activity is demonstrated in 2 hr incubations of the SMP with 10-100-mu-M DX in air-equilibrated medium with excess NADH to support redox-cycling of the drug. This oxidative mechanism for oxidase inactivation occurs in connection with a peroxidation process in the bulk membrane lipid, and is independent on turnover of the enzyme. It is related in a complex manner to the electron flux in the respiratory chain with antioxidant properties, and is maximal at the high reduction level of respiratory chain Complex I obtained in the presence of rotenone. Reduction of DX per se plays a minor role, and trace concentrations of chelatable metal ions (iron) are required to catalyse the reaction. Iron in the iron storage protein ferritin is released by DX, and at physiological low O2 concentrations ([O2] < 20-mu-M), this iron is a better promoter of oxidase inactivation than is endogenous iron in the SMP. Kinetic analysis of inactivation data indicates the interaction of DX with low affinity (K(m) 35-55-mu-M) binding sites in the SMP membranes. Overall, the results point to the possible role of ferritin-iron in the mechanism of DX mitochondrial toxicity and argue against site specific effects of the DX-reduction/oxidation cycle on the cytochrome c oxidase or on its essential phospholipid (cardiolipin) environment.
引用
收藏
页码:543 / 552
页数:10
相关论文
共 64 条
[1]  
ARNOLD LJ, 1985, METHOD ENZYMOL, V112, P270
[2]  
BARTLETT GR, 1959, J BIOL CHEM, V234, P466
[3]  
Beinert H, 1978, Methods Enzymol, V54, P435
[4]  
Buege J A, 1978, Methods Enzymol, V52, P302
[5]  
BURKE TG, 1987, CANCER BIOCHEM BIOPH, V9, P245
[6]   REACTIONS OF THE SEMIQUINONE FREE-RADICALS OF ANTI-TUMOR AGENTS WITH OXYGEN AND IRON COMPLEXES [J].
BUTLER, J ;
HOEY, BM ;
SWALLOW, AJ .
FEBS LETTERS, 1985, 182 (01) :95-98
[7]  
CHENEVAL D, 1985, J BIOL CHEM, V260, P3003
[8]  
DAVIES KJA, 1986, J BIOL CHEM, V261, P3060
[9]   NADH OXIDATION IN SUBMITOCHONDRIAL PARTICLES PROTECTS RESPIRATORY-CHAIN ACTIVITY AGAINST DAMAGE BY ADRIAMYCIN-FE-3+ [J].
DEMANT, EJF .
EUROPEAN JOURNAL OF BIOCHEMISTRY, 1983, 137 (1-2) :113-118
[10]  
DEMANT EJF, 1983, EUR J BIOCHEM, V132, P551