Figure 2

Effect of site-specific inhibitors on OXPHOS component activities in MCF-7 cells over time. Bars depicting CI, CII, CIII, CIV and CV inhibitor-sensitive catalytic activities normalized to protein equivalent (pkat/mg) (A,C,E,G,I) or citrate synthase (CS) activity (unitless) (B,D,F,H,J) after incubation for 24 h, 48 h and 72 h at 37 °C under 5% CO₂ atmosphere in assay media containing the respective RC inhibitor. The inhibitors (5 µM rotenone for CI, 1 µM atpenin A5 for CII, 1 µM myxothiazol for CIII, 1 mM azide for CIV, 5 µM oligomycin for CV) sustained complete or near complete inhibition of the respective complex for the entire duration of the experiment (grey bars), compared to untreated cells (black bars). Data indicate the mean of three biological replicates and error bars indicate 1 standard deviation. *a: p < 0.05; *b: p < 0.001.