2‐n‐Nonyl‐4‐hydroxy [3‐³H] quinoline N‐oxide: Interaction with the Mitochondrial Membrane

Synthesized 2-n-nonyl-4-hydroxy[3-3H]quinoline N-oxide ([3H]NoHOQnO) is a powerful inhibitor of both NADH oxidase and succinate oxidase activities in submitochondrial particles from beef heart. 2. The binding of [3H]NoHOQnO to submitochondrial particles reveals one specific binding site, which is sensitive to antimycin, and a large amount of aspecific binding. 3. The content of [3H]NoHOQnO-specific binding sites is related to the cytochrome b content in the particles. 4. The binding of [3H]NoHOQnO to the specific site causes the inhibition of electron transfer. 5. The relation between the inhibition of NADH oxidation and [3H]NoHOQnO-specific binding is hyperbolic.