STUDIES ON MITOCHONDRIAL ADENOSINE TRIPHOSPHATASE SYSTEM .3. ISOLATION FROM OLIGOMYCIN-SENSITIVE ADENOSINE TRIPHOSPHATASE COMPLEX OF FACTORS WHICH BIND F1 AND DETERMINE OLIGOMYCIN SENSITIVITY OF BOUND F1

The oligomycin-sensitive adenosine triphosphatase (ATPase) complex after extraction with salt solutions in relatively high concentrations (>2 M) is resolvable into a soluble and particulate fraction. The soluble fraction contains protein which can be identified with F1 subunits. The particulate fraction contains 20% by weight of lipid and is devoid of ATPase activity. When F1 is added back to the particulate fraction, there is rebinding of F1 to the particles and this rebinding can be correlated with the restoration of oligomycin-sensitive ATPase activity. The salt-extracted, ATPase-free residue after exposure to dilute alkali (pH 11.5) can still bind F1 but the particle-bound ATPase thus reconstituted is not oligomycin sensitive. The thesis that there is a specific protein required for binding of F1 as well as a specific protein for conferring oligomycin sensitivity is compatible with the experiments described in the present communication. © 1968, American Chemical Society. All rights reserved.