Effect of MI‐D, a new mesoionic compound, on energy‐linked functions of rat liver mitochondria

FEBS Letters

de Oliveira, Maria Benigna M¹  Echevarria, Aurea²  Cadena, Silvia M.S.C¹  Carnieri, Eva G.S¹ 

[1] Departamento de Bioquı́mica, Universidade Federal do Paraná, C.P. 19046, C.E.P. 81531-990, Curitiba, Paraná, Brazil;Departamento de Quı́mica, Universidade Federal Rural do Rio de Janeiro, Rio de Janeiro, Brazil

关键词: Mesoionic compound;    Mitochondrial uncoupling;    ATPase;    HEPES;    N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid;    EGTA;    ethylene glycol-bis(β-aminoethylether)-N;    N;    N′;    N′-tetraacetic acid;    BSA;    bovine serum albumin;    PMS;    N-methyldibenzopyrazine methyl sulfate;    Tris;    tris(hydroxymethyl)aminomethane;    PEP;    phosphoenolpyruvate;    CCCP;    carbonylcyanide-m-chlorophenylhydrazone;    FCCP;    carbonylcyanide p-trifluoromethoxyphenylhydrazone;    DNP;    2;    4-dinitrophenol;    Δψ;    transmembrane electrical potential;    DMPC;    dimyristoylphosphatidylcholine;    DMSO;    dimethylsulfoxide;    DPIP;    2;    6-dichlorophenolindophenol;    Pi;    inorganic phosphate;   

DOI  :  10.1016/S0014-5793(98)01427-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

MI-D (4-phenyl-5-(4-nitro-cinnamoyl)-1,3,4-thiadiazolium-2-phenylamine chloride), a new mesoionic compound, depressed the phosphorylation efficiency of liver mitochondria as deduced from an accentuated decrease of the respiratory control coefficient and ADP/O ratio. Analysis of segments of the respiratory chain suggested that the MI-D inhibition site is further on than complex I and between complexes II and III. The transmembrane electrical potential (Δψ) was collapsed dependent on MI-D concentration. ATPase activity was dramatically increased by MI-D in intact mitochondria, but inhibited in carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP)-uncoupled mitochondria. These results suggest that MI-D acts as an uncoupler agent, a property closely related to its structural characteristics.

【 授权许可】

Unknown