Table 2. Rate constants for O₂ and chelator-promoted [4Fe–4S] cluster conversion/degradation at 25 °C.

Iron chelator	Aerobic/anaerobic	Rate constant (min–1)
—	+O2 (59–230 μM)	1.9 (±0.4) × 10–2
EDTA
1 mM	–O2	2.6 (±0.4) × 10–3
	+O2 (230 μM)	8.5 (±0.4) × 10–3
4 mM	–O2	5.0 (±0.8) × 10–3
Chelex	–O2	2.4 (±0.4) × 10–3
	+O2 (230 μM)	6.1 (±0.7) × 10–2