Table II.
Dissociation Constants (KD) for Cd2+ Block of Double Mutants Observed before and after DTT Reduction (Means ± SEM)
| Y401C | W402C | E403C | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Observed K D (μM) | Observed K D (μM) | Observed K D (μM) | ||||||||||
| Nonreduced | Reduced | Nonreduced | Reduced | Nonreduced | Reduced | |||||||
| W756C | 1.2 ± 0.1 × 10 (3) | 1.2 ± 0.1 × 10 (3) | 1.4 ± 0.1 × 102 (3) | 1.4 ± 0.2 × 102 (2) | 2.4 ± 0.3 × 102 (4) | 2.4 ± 0.2 × 102 (2) | ||||||
| 1757C | 2.1 ± 0.4 (5)* | 2.1 ± 0.5 (2)* | n.e. | n.e. | 1.4 ± 0.2 × 102 (7) | 1.1 ± 0.3 × 102 (2) | ||||||
| E758C | 1.2 ± 0.1 × 103 (8)* | 9.3 ± 1.8 × 10−1 (5)* | 2.5 ± 0.7 × 10−1 (7)* | 2.5 ± 1.0 × 10−1 (3)* | 1.6 ± 0.9 × 102 (5) | 1.9 ± 0.2 × 10 (5)* | ||||||
| W1239C | 7.8 ± 5.5 × 10−1 (5)* | 1.1 ± 0.3 (3)* | 1.2 ± 0.1 × 10 (7)* | 1.3 ± 0.1 × 10 (3)* | 3.7 ± 0.2 × 10 (6) | 3.2 ± 0.2 × 10 (3) | ||||||
| M1240C | 6.0 ± 0.3 (7)* | 6.1 ± 0.1 (2)* | 2.3 ± 0.7 (7)* | 3.0 ± 0.1 (3)* | 1.6 ± 0.4 × 102 (8) | 1.6 ± 0.3 × 102 (3) | ||||||
| D1241C | 4.7 ± 0.7 (5)* | 6.3 ± 0.6 (4)* | 5.2 ± 0.6 × 10 (9)* | 2.8 ± 0.3 × 10 (4)* | 1.3 ± 0.1 × 102 (9)* | 1.2 ± 0.2 × 102(3)* | ||||||
| A1529C | 2.1 ± 0.5 × 102 (4)* | 2.1 ± 0.1 (3)* | 1.1 ± 0.5 × 10 (5) | 1.2 ± 0.2 × 10 (3) | 1.5 ± 0.3 × 103 (7)* | 5.9 ± 1.8 (3)* | ||||||
| G1530C | 1.8 ± 0.6 (7)* | 1.4 ± 0.4 (2)* | 4.4 ± 0.5 × 10 (7) | 4.8 ± 0.8 × 10 (2) | 3.6 ± 1.7 × 103 (6)* | 8.3 ± 1.2 (5)* | ||||||
| W1531C | 4.2 ± 1.0 (7)* | 4.2 ± 0.8 (3)* | 1.9 ± 0.3 × 10 (8)* | 6.4 ± 0.9 (3)* | 9.7 ± 5.0 × 10 (7)* | 6.4 ± 1.0 (6)* | ||||||
| D1532C | 4.2 ± 1.4 (7)* | 2.4 ± 0.3 (4)* | 3.0 ± 1.0 × 10 (6)* | 7.9 ± 3.6 (4)* | 5. 1 ± 1.6 × 102 (5) | 7.2 ± 2.6 (4)* | ||||||
Mutants that are statistically different (p < 0.05) from the predicted values are indicated by asterisks. Numbers in parentheses represent the number of determinations. n.e., no expression.