Table 2.

Kinetic parameters for the newly obtained enzyme from MreCA, compared with the human hCA II (α-class) and the β-class enzyme from MgCA at 25 °C, pH 8.3 in 20 mM Tris buffer and 20 mM NaClO₄, for the CO₂ hydration reaction.

Isozyme	kcat (s−1)	KM (mM)	kcat/KM (M−1 s−1)	KI (AAZ) (nM)
hCA II	1.4 × 106	9.3	1.4 × 108	12
MgCA	9.2 × 105	11.1	8.3 × 107	74,000
MreCA *	1.06 × 106	10.1	1.07 × 108	50.7

* The kinetic/inhibition parameters are the mean from 3 different assays. Errors are in the range of 10% of the reported values (material not intended for publication).