Table 1. Rate constants for the early steps of O2 reduction at low and high temperature for pH 7 and 10, respectively.
Errors are the SDs for n = 3 (pH 10 data) or n = 4 (pH 7 data) measurements.
| Rate constant (s−1) (Time constant) (μs) | |||
| T (°C) | pH 7 | pH 10 | |
| O2 binding (610-nm decay) | 10 | (2.8 ± 0.8) × 105 (3.6) | (2.9 ± 0.1) × 105 (3.4) |
| 45 | (2.7 ± 0.8) × 105 (3.7) | (4 ± 1) × 105 (2.5) | |
| Heme b oxidation (kb) (560-nm decay) | 10 | (9 ± 4) × 104 (11) | (2.6 ± 0.6) × 104 (38) |
| 45 | (1.9 ± 0.2) × 105 (5.3) | (1.9 ± 0.2) × 105 (5.3) | |
| PR formation (kP) (610-nm increase) | 10 | (9 ± 1) × 103 (110) | (8.7 ± 0.3) × 103 (120) |
| 45 | (1.8 ± 0.5) × 105 (5.5) | (1.5 ± 0.5) × 105 (6.7) | |
| Ratio (kb/kP) | 10 | 10 | 3 |
| 45 | 1.1 | 1.3 | |