Table 3. Catalytic parameters of TcruCA and hCA II.

Parameter	TcruCA	hCA II†
k cat ex/ (M 1s1)	11.0 0.1	120
k B (s1)	0.30 0.05	0.8
‡	6.6 0.1	6.9
§	6.4 0.2	6.8
pK a,PSR §	6.4 0.2	7.2

^†Metcalf et al. (1996 ▸). Standard errors are no larger than 20%.

^‡Determined by ¹⁸O-exchange from calculation of k _cat ^ex/ in the hydration of CO₂.

^§Determined from calculation of /[E].