Fig. 3.

NADH-oxidase activity of membranes with different CL content. Membranes were isolated from cells incubated in hypoxic conditions for either 1 or 2 h (M1 and M2, respectively) and then solubilized, as described in Section 2. Lipid quantitative analysis and spectral assay were performed on M1 and M2. (A) Molar ratio of CL to heme a of M1 and M2 membranes. Heme a content was estimated spectrophotometrically. (B) NADH-oxidase activity of M1 and M2 membranes (100 ng of membrane proteins each). (C) KCN titration of membrane oxidase activity. The NADH-oxidase activities of membranes are reported as percent activity in response to addition of increasing amounts of KCN (0–5 μM).