Table 4.
Kinetic parameters for heme binding to selected heme-proteins.
| Protein (ref.) | kon (μM s)-1 | k-heme (s-1) | Ka (M-1) | Method |
|---|---|---|---|---|
| Rv0203-notag (this work) | 133 ± 19 | Single Exp: 8.2 × 10-2 ± 1.6 × 10-2 | 1.6 × 109 (single exp.) | Stopped flow |
| Double Exp: kf (22%): 7.7 × 10-1 ± 5.7 × 10-2 ks: 5 × 10-2 ± 1 × 10-2 | ||||
| Rv0203-His (this work) | 115 ± 30 |
kf (31%): 1.9 × 10-3 ± 6 × 10-4 ks: 2 × 10-4 ± 1 × 10-4 |
5.8 × 1011 M-1 (using slow phase for k-heme) | Stopped flow |
| Mb (31) | 70 | 8.4 × 10-7 | 8×1013 | Stopped flow |
| H93G-Mb (31) | 70 | 1.2 × 10-2 | 6 × 109 | Stopped flow |
| BSA (31) | ~50 | 1.1 × 10-2 | 4 × 109 | Stopped flow |
| IsdA (46) | 100 | 2.6 × 10-4 | 3.8 × 1011 | Stopped flow |
| IsdB(47) | kf: 2.8 × 10-2, ks: 4.2 × 10-3 | > 2.6 × 106 | Stopped flow, Fluorescence titration | |
| Shp (48) | 1.6 | 3 × 10-4 | 5.3 × 109 | Stopped flow |
| HtsA (48) | 80 | 2.6 × 10-3 | 3.1 × 1010 | Stopped flow |
| HasA (15) (25) | 16 | 3 × 10-4 (calculated from k-heme = kon/Ka) | 5.3 × 1010 | Stopped flow, ITC |
| PhuS (49) | 0.18 (calculated from kon=Ka*k-heme) | 3.6 × 10-2 | 5.0 × 106 | Fluorescence titration |
| HmuT (50) | 3.4 × 109 (1st heme molecule) | ITC |