Table 2. ITC binding parameters for pyocins titrated into LPS sugars from P. aeruginosa PAO1.
*Errors in parentheses refer to errors from fit of data from individual experiments to a single-binding site model. †Mean of the two independent experiments (±S.E.M.). ‡N fixed to 0.10 for fitting (see Materials and methods). ND–not determined.
| Pyocin | [Protein] (μM) | [LPS sugars] (mg·ml−1) | ΔH (±)* (kcal·mol−1) | N (±)* (sites) | ΔS (cal·mol−1·deg−1) | Kd (±)* (μM) | Average Kd (±)† (μM) |
|---|---|---|---|---|---|---|---|
| SD2 | 300 | 3.0 | −25.0 (2.4) | 0.11 (0.01) | −55 | 0.93 (0.09) | 0.58 (0.36) |
| SD2 | 150 | 3.0 | −17.4 (0.7) | 0.11 (0.00) | −28 | 0.22 (0.02) | |
| S2 | 75 | 3.0 | −16.6 (0.6) | 0.12 (0.00) | −24 | 0.14 (0.03) | 0.38 (0.24) |
| S2 | 150 | 3.0 | −18.3 (0.9) | 0.11 (0.00) | −33 | 0.62 (0.04) | |
| S5 | 300 | 3.0 | −28.5 (3.9) | 0.13 (0.01) | −68 | 1.94 (0.19) | 1.19 (0.75) |
| S5 | 150 | 3.0 | −17.9 (0.6) | 0.14 (0.00) | −31 | 0.44 (0.01) | |
| AP41 | 100 | 1.0 | ND | – | − | – | – |
| AP41 | 150 | 3.0 | ND | – | − | – | |
| SD1 | 300 | 3.0 | ND | – | − | – | – |
| SD1 | 300 | 3.0 | ND | – | − | – | |
| SD3 | 257 | 3.0 | −23.4 (2.8) | 0.10 (0.01) | −51 | 1.84 (0.17) | 1.47 (0.37) |
| SD3 | 150 | 3.0 | −16.3 (0.9) | 0.12 (0.00) | −27 | 1.10 (0.04) | |
| S2Δ318 | 257 | 3.0 | ND | – | − | – | – |
| S2Δ318 | 150 | 3.0 | ND | – | − | – | |
| S2(209) | 300 | 3.0 | ND | – | − | – | – |
| S2(209) | 175 | 1.0 | ND | – | − | – | |
| SD2Δ216 | 300 | 3.0 | −47.0 (4.0) | 0.10‡ | −134 | 21.32 (0.55) | 22.31 (0.99) |
| SD2Δ216 | 300 | 3.0 | −67.8 (5.8) | 0.10‡ | −203 | 23.29 (0.59) |