Fig. 4.

H₂O₂ release of human PMN inhibited by zinc and chelated by EGTA.

A) In three independent experiments over of 90 min H₂O₂ release was measured. Zinc concentrations from 1 μM to 3 mM inhibit H₂O₂ release. Data is displayed as Mean. EGTA was added at ≈ 16 min. Overall release of H₂O₂ is seen at 90 min. Maximal rate of production is determined at the steepest slope of H₂O₂ release over time. Data was normalized to a single cell. B) Dose-response curve giving an IC₅₀ = 14 μM Zn²⁺. C) Dixon Plot fitted with a Michaelis-Menten-Equation showing an apparent K_M = 67 μM Zn²⁺.