Table 3.

Inhibition Constants for Anionic Inhibitors of Human Isozymes hCA I, hCAII, and hCAXII and Mutant hCA XII for the CO₂ Hydration Reaction at 20°C¹⁴

Inhibitor	KIa			[mM]
	hCA I	hCA II	hCA XII	Mutant hCA XII
F−	> 300	> 300	0.56	0.59
Cl−	6	200	73	0.49
Br−	4	63	82	0.37
I−	0.3	26	215	0.73
CNO−	0.0007	0.03	0.73	0.58
SCN−	0.2	1.6	0.80	0.52
CN−	0.0005	0.02	0.001	0.004
N3−	0.0012	1.5	0.08	0.005
HCO3−	12	85	0.75	0.67
CO32−	15	73	0.64	0.47
NO3−	7	35	79	0.58
NO2−	8.4	63	94	0.64
HS−	0.0006	0.04	4.85	0.54
HSO3−	18	89	0.84	0.92
SO42−	63	> 200	0.77	0.74
BF4−	> 200	> 200	> 200	> 200
H2NSO3Hb>	0.021	0.39	0.70	7.6 μM
H2NSO2NH2	0.31	1.13	0.83	6.5 μM
PhB(OH)2	58.6	23.1	0.80	6.1 μM
PhAsO3H2b	31.7	49.2	0.84	5.2 μM

^aErrors were in the range of 3%–5% of the reported values, from three different assays.

^bAs sodium salt.