A – EPR spectrum of etoposide phenoxyl radical generated by cyt c/TOCL complex in the presence of H2O2. B – Relative intensity of EPR signal in the presence of liposomes of different composition: DOPC only, DOPC/TOCL (1:1), DOPC/NBD-CL (1:1). Incubation conditions: phospholipid concentration 1 mM, cyt c 20 μM, etoposide 200 μM, H2O2 100 μM, incubation time 4 min. C – Effect of NBD-CL on oxidation of West Femto sensitive substrate by cyt c/H2O2. Conditions: 5 nM cyt c was mixed with liposomes (DOPC/TOCL 1:1) containing either non-labeled, or labeled TOCL, total volume 100 μL. Reaction was started by addition of substrate solution already containing H2O2.