Interaction between the oligomycin sensitivity conferring protein and the F0 sector of the mitochondrial adenosinetriphosphatase complex: cooperative effect of the F1 sector
Beef heart mitchondrial oligomycin sensitivity conferring protein (OSCP) labeled with (/sup 14/C)-N-ethylmaleimide ((/sup 14/C)OSCP) at the only cysteine residue, Cys-118, present in the sequence. The binding parameters of (/sup 14/C)OSCP with respect to the F0 sector of submitochondrial particles largely depleted of F1 and OSCP (AUA particles) have been explored. In the absence of added F1, a limited number of high-affinity OSCP binding sites were detected in the AUA particles (20-40 pmol/mg of particles); under these conditions, the low-affinity binding sites for OSCP were essentially not saturable. Addition of F1 to the particles promoted high-affinity binding for OSCP, with an apparent Kd of 5 nM, a value 16 times lower than the Kd relative to the binding of OSCP to F1 in the absence of particles. Saturation of the F1 and OSCP binding sites of AUA particles was attained with about 200 pmol of both F1 and OSCP added per milligram of particles. The oligomycin-dependent inhibition of F1-ATPase bound to AUA particles was assayed as a function of bound OSCP. At subsaturating concentrations of F1, the dose-effect curves were rectilinear until inhibition of ATPase activity by oligomycin was virtually complete, and maximal inhibition was obtained for an OSCP to F1 ratio of 1 (mol/mol).(ABSTRACT TRUNCATED AT 250 WORDS)
- Research Organization:
- Centre d'Etudes Nucleaires de Grenoble, France
- OSTI ID:
- 6528586
- Journal Information:
- Biochemistry; (United States), Vol. 2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Synthesis and properties of azidonitrophenyl pyrophosphate, a photoaffinity probe of the nucleotide binding sites of mitochondrial F1-ATPase
Chemical modification of thiol groups of mitochondrial F1-ATPase from the yeast Schizosaccharomyces pombe. Involvement of alpha- and gamma-subunits in the enzyme activity
Related Subjects
MITOCHONDRIA
BIOCHEMISTRY
PROTEINS
BIOCHEMICAL REACTION KINETICS
ATP-ASE
CARBON 14 COMPOUNDS
CATTLE
ENZYME ACTIVITY
HEART
ACID ANHYDRASES
ANIMALS
BODY
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
CHEMISTRY
DOMESTIC ANIMALS
ENZYMES
HYDROLASES
KINETICS
LABELLED COMPOUNDS
MAMMALS
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
PHOSPHOHYDROLASES
REACTION KINETICS
RUMINANTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques