TABLE 2.
Properties of allantoinase purified from zinc-, cobalt-, and nickel-amended cultures and nonamended cultures
| Culture | Allantoin Km (mM) | kcat (min−1) | DTT Ki (μM) | No. of mol of metal/mol of monomera
|
Isomer preference | |||
|---|---|---|---|---|---|---|---|---|
| Zn | Co | Fe | Ni | |||||
| Zinc amended | 17.0 ± 2.7 | 5,000 ± 250 | 237 | 1.44 | 0.00 | 0.38 | 0.00 | S |
| Cobalt amended | 19.5 ± 1.3 | 28,200 ± 540 | 795 | 0.12 | 1.00 | 0.17 | 0.00 | S (fast), R (slow) |
| Nickel amended | 79.9 ± 5.5 | 200 ± 5 | NDb | 0.00 | 0.00 | 0.62 | 0.13 | ND |
| Nonamended | ND | 34.7c | ND | 0.03 | 0.00 | 1.08 | 0.00 | ND |
a
Values are shown for representative samples.
b
ND, not determined.
c
Measured at 50 mM allantoin.