Energization of the membrane prevents the formation of tight inactive complexes of ATPase with MgADP in submitochondrial particles

FEBS Letters

Chernyak, B.V.¹  Khodjaev, E.Yu.¹ 

[1] A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, Moscow 119899, USSR

关键词: Mitochondrial enzyme;    ATPase;    H+-;    Enzyme-MgADP complex;    Mg;    Mn-SMP and S-SMP;    different types of submitochondrial particles;    CCCP;    carbonyl cyanide m-chloro-phenylhydrazone;   

DOI  :  10.1016/0014-5793(89)81013-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Mitochondrial ATPase binds ADP tightly, forming inactive complexes. Dissociation of the complexes is blocked by azide. Azide inhibits neither ATP hydrolysis at high δH⁺ nor ATP-dependent NAD⁺ reduction, provided that the ADP concentration is higher than 10⁻⁴ M. At lower ADP levels, azide is inhibitory. These data suggest that in the presence of ATP δH⁺ prevents the fromation of one of the inactive complexes. In the absence of ATP at high δH⁺, azide-sensitive complexes are not formed at any ADP concentrations tested (5 × 10⁻⁷-5 × 10⁻⁴ M). The inactive E·ADP complexes can play a significant role in the regulation of ATPase in mitochondria, preventing futile ATP hydrolysis at low δH⁺.

【 授权许可】

Unknown