Spectra of cyt. c (native) and cm cyt. c. I, the dithionite reduced (deoxy) form of cyt. c; II, the deoxy form of cyt. c/CL; III, the deoxy form of cyt. c/CL/NO; IV, the deoxy form of cm cyt. c/NO. Conditions: [cyt. c] = 8 μm, [CL] = 240 μm, [NO] = 100 μm. Inset, EPR spectra of native and cm cyt. c (a) cm cyt. c + NO (the spectrum for M80A cyt c + NO was identical) (b) cm cyt. c + CL + NO (c) cyt. c + CL + NO. Conditions: [cyt. c] = 20 μm, [CL] = 500 μm, [NO] = 100 μm, temperature for all samples was 10 K and microwave frequency and power for all samples was 9.47 GHz and 3.18 milliwatt, respectively.