Electron paramagnetic resonance of the mitochondrial respiratory chain in the presence of phenazine methosulfate.

The EPR spectra of phenazine methosulfate (PMS) generated under different conditions, as reduction or excitation with light were studied. In addition, results show the EPR spectra of reduced-submitochondrial particles and reduced-submitochondrial particles in the presence of PMS. Combined systems of this last type have been repeatedly utilized in EPR studies. This work proves that such systems give rise to characteristic signals around g = 2, which behaviour reflects the presence of particular prosthetic groups of the respiratory chain combined with the reduced dye. The consequences of these findings are discussed.