Isozyme | Activity level | k
cat
(s
-1
) | k
cat
/K
m
(M
-1
s
-1
) | K
I
(nM)
c |
|---|
HCA I
a
| moderate | 2.0 × 105 | 5.0 × 107 | 250 |
HCA II
a
| very high | 1.4 × 106 | 1.5 × 108 | 12 |
Can2
a
| moderate | 3.9 × 105 | 4.3 × 107 | 10.5 |
Nce103
a
| high | 8.0 × 105 | 9.7 × 107 | 132 |
ScCA
a
| high | 9.4 × 105 | 9.8 × 107 | 82 |
CgCA
a
| moderate | 3.8 × 105 | 4.8 × 107 | 11 |
DmBCA
b
| high | 9.5 × 105 | 1.1 × 108 | 49 |
- Kinetic parameters for the human cytosolic isozymes human HCA I and II (α-class CAs) at 20°C and pH 7.5 in 10 mM HEPES buffer and 20 mM Na2SO4, in addition to the β-CAs Can2, Nce103 (from C. neoformans and C. albicans, respectively), ScCA (from S. cerevisiae), CgCA (from C. glabrata) and DmBCA (from Drosophila melanogaster) measured at 20°C, pH 8.3 in 20 mM Tris buffer and 20 mM NaClO4 are shown. Inhibition data with the clinically used sulfonamide acetazolamide (5-acetamido-1,3,4-thiadiazole-2-sulfonamide) are also provided.
- aReference [30]
- bThis work
- cacetazolamide
