Extended Data Fig. 7: Persulfides are superior radical scavengers.
From: Hydropersulfides inhibit lipid peroxidation and ferroptosis by scavenging radicals
(A) Scheme explaining the autoxidation of Amplex Red (ROH) in the presence of GSH, APEX2 and O2. APEX2-generated phenoxyl radicals (RO·) react with GSH to form glutathionyl radicals (GS·). These react further with GSH and O2 to produce superoxide radicals (O2.-), which dismutate to yield H2O2, in turn driving APEX2 activity. Phenoxyl radicals of Amplex Red disproportionate to form Amplex Red and resorufin. (B) Influence of oxygen partial pressure (1% vs. 21%) on resorufin formation in the presence of APEX2 (2 µM) and Amplex Red (100 µM), with or without GSH (1 mM) (left panel). Influence of DEPMPO (20 mM) on resorufin formation in the presence of APEX2 (2 µM) and Amplex Red (100 µM), with or without GSH (1 mM) (right panel). n = 2. (C) Influence of increasing concentrations of Na2S4 on resorufin formation in the presence of APEX2 (2 µM), Amplex Red (100 µM), GSH (1 mM) and 21% O2 (left panel). The relationship between Na2S2 concentration and inhibition time (left axis) allows quantification of eliminated radicals (right axis), using a calibration curve (right panel). n = 2. (D) Influence of Na2S (10 µM) on resorufin formation in the presence of APEX2 (2 µM), Amplex Red (100 µM), GSH (1 mM) and 21% O2. The influence of Na2S4 (10 µM) is shown for comparison (left panel). The relationship between Na2S concentration and inhibition time, shown in comparison to Na2S4 (right panel). n = 2. Data are presented as mean values.
