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Energization of the membrane prevents the formation of tight inactive complexes of ATPase with MgADP in submitochondrial particles
Author(s) -
Chernyak B.V.,
Khodjaev E.Yu.
Publication year - 1989
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(89)81013-0
Subject(s) - submitochondrial particle , atp hydrolysis , azide , chemistry , atpase , adenosine triphosphate , dissociation (chemistry) , mitochondrion , chemiosmosis , biochemistry , biophysics , atp synthase , nad+ kinase , hydrolysis , adenosine diphosphate , f atpase , enzyme , biology , organic chemistry , platelet , platelet aggregation , thylakoid , chloroplast , gene , immunology
Mitochondrial ATPase binds ADP tightly, forming inactive complexes. Dissociation of the complexes is blocked by azide. Azide inhibits neither ATP hydrolysis at high δ H + 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 δ H + prevents the fromation of one of the inactive complexes. In the absence of ATP at high δ H + , 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 δ H + .