Table 1.

Rate constants of SO dismutation by SODs and nanozymes at pH 12.7

Catalyst	biphasic ratea, s−1		[catalyst]	2nd-order rate constantb, M−1s−1		FQ-EPR kcat, s−1/KM, mM
	k1’	k2’		k1	k1
CuZnSOD	0.33 ± 0.005	0.26 ± 0.021	20 nM	1.7 (± 0.3) × 107	1.3 (± 0.1) × 107	4.4 × 104/2.7d
MnSOD	0.70 ± 0.003	0.68 ± 0.016	20 nM	3.5 (± 0.02) × 107	3.4 (± 0.08) × 107	1.8 × 105/10.2d
FeSODc	0.05 ± 0.005	0.043 ± 0.016	20 nM	2.5 (± 0.3) × 106	2.2 (± 0.8) × 106	N.D.e
PEG-HCCs	2.66 ± 0.11	1.16 ± 0.059	20 nM	1.3 (± 0.06) ×108	5.8 (± 0.3) × 107	2.0 × 105/0.75f
PEG-aGQDs	2.01 ± 0.130	0.10 ± 0.026	20 nM	1.0 (± 0.07) × 108	4.9 (± 1.3) × 106	2.9 × 105/6.5g
PEG-bGQDs	0.81 ± 0.063	0.36 ± 0.031	20 nM	4.1 (± 0.3) × 107	1.8 (± 0.2) × 107	1.0 × 105/32g
C3	0.057 ± 0.003	0.06 ± 0.005	2 μM	2.9 (± 0.2) × 104	3.0 (± 0.3) × 104	1.1 /11.5d
C60-OHn	0.046 ± 0.003	0.04 ± 0.004	30 μM	1.5 (± 0.1) × 103	1.3 (± 0.1) × 103	3.0/19d

^aexponential fit using eq 7

^bk = k’/[catalyst]

^cFeSOD did not show any significant SO consumption activity at this pH although its time course was fit well with eq 7

^dthis study; measured in the same way as in ref¹⁷ except in the freeze-trapping preparation of each EPR sample, SOD was diluted individually into each reaction mixture immediately before the reaction was started since both CuZnSOD and MnSOD gradually lost activity at pH 12.7; larger data scattering (n = 4) was thus observed in the SOD samples than in the nanozyme samples

^enot determined, FeSOD deactivated rapidly at this pH

^fref¹⁷

^gref¹⁸.