Figure 5. Purified murine PGHS-2 catalytically consumes NO via peroxidase turnover.

(A) (i) Decay of 3.8 μM NO in Tris buffer, pH 7.8, at 37 °C; (ii) decay of NO in buffer with 6.2 μM 15(S)-HPETE; (iii) purified PGHS-2 (20 nM) was added to buffer containing 3.8 μM NO and 6.2 μM 15(S)-HPETE as shown. (B) (i) Purified murine PGHS-2 (20 nM) was added to buffer with 3.8 μM NO alone; (ii) apo-PGHS-2 (20 nM) was added to buffer containing 6.2 μM 15(S)-HPETE and 3.8 μM NO; (iii) haematin (40 nM) was added to buffer containing 6.2 μM 15(S)-HPETE and 3.8 μM NO. (C) (i) Decay of NO in buffer containing 500 μM H₂O₂; (ii) purified PGHS-2 (20 nM) was added to buffer containing 500 μM H₂O₂ and 3.8 μM NO; (iii) apo-PGHS-2 (20 nM) was added to buffer containing 500 μM H₂O₂ and 3.8 μM NO; (iv) haematin (40 nM) was added to buffer containing 500 μM H₂O₂ and 3.8 μM NO.