Table 1.

BteCAι kinetic parameters compared with those calculated for the two human isoforms hCA I and II (α-class), and the α-, β-, γ- and ι-CAs from different bacterial species (all of them with Zn(II) at the active site).

Organisms	Acronym	Class	Kcat (s–1)	kcat/KM (M–1·s–1)
Homo sapiens	hCA Ia	α	2.0 × 105	5.0 × 107
	hCA IIa	α	1.4 × 106	1.5 × 108
Vibrio cholerae	VchCAb	α	8.23 × 105	7.0 × 107
Burkholderia pseudomallei	Bps βCAc	β	1.6 × 105	3.4 × 107
Burkholderia pseudomallei	BpsγCAd	γ	5.3 × 105	2.5 × 107
Burkholderia territorii	BteCAιe	ι	3.0 × 105	9.7 × 107

The CO₂ hydration reaction was followed at 25 °C, in 20 mM Tris buffer and 20 mM NaClO4, pH 8.3. ^aFrom ref. 3; ^bFrom ref. 28; ^c,dFrom ref. 10; ^eThis work.