Fig. 2.

CO, CORM-3 and CORM-2 inhibit respiration in wild type E. coli membrane particles. Wild type E. coli membrane particles were added to an oxygen electrode chamber in buffer (2 ml) to a final concentration of approximately (A) 60 μg/ml, (B) 170 μg/ml, or (C) 100 μg/ml. The chamber was closed and respiration was initiated by the addition of 6.25 mM NADH. CO and CO-RMs were then added as indicated at approximately 75% of oxygen saturation (310 nmol O₂ in the chamber). Traces show dissolved oxygen in the chamber as follows: (A) control (black solid line) and 100 μM CO (blue broken line); (B) control (black solid line), 100 μM iCORM-3 (red dot dash line), 100 μM CORM-3 (blue short dash line), 400 μM CORM-3 (blue long dash line); (C) control (black solid line), 100 μM RuCl₂(DMSO)₄ (red dot dash line), 50 μM CORM-2 (blue short dash line), 100 μM CORM-2 (blue long dash line). Respiration rates (nmol min^− 1 mg^− 1 protein) 2 min following the addition of CO-RM are shown adjacent to each trace. These data are representative of at least 3 technical and 2 biological replicates.