TABLE 1.
Thermodynamic binding parameters of CHIPS31-121:C5aR peptide complexes determined by ITC
C5aR peptides are numbered according to Swiss-Prot entry P21730. The presence of sulfate groups on tyrosine residues 11 and 14 is indicated by S2. The data are averages from at least three independent experiments unless indicated otherwise (mean ± S.E.). The errors in the thermodynamic parameters were estimated by Monte Carlo simulations using the standard deviations of the individual experiments. The average stoichiometric value n = 1.13 ± 0.04 (the error bound represents ± S.E.; n = 14).
| Peptide | Kd | ΔG | ΔH | ΔS |
|---|---|---|---|---|
| nm | kJ mol−1 | kJ mol−1 | J K−1 mol−1 | |
| C5aR10-18 | −a | − | − | − |
| C5aR7-28 | (3.2 ± 0.1) × 103 | −31.3 ± 0.1 | −78.0 ± 2.5 | −157 ± 8 |
| C5aR10-18S2 | (15.9 ± 1.4) × 103 | −27.4 ± 0.2 | −41.9 ± 3.1 | −49 ± 10 |
| C5aR10-24S2b | 24.7 ± 0.4 | −43.4 ± 0.1 | −85.4 ± 0.3 | −141 ± 1 |
| C5aR7-28S2 | 8.4 ± 1.1 | −46.1 ± 0.3 | −94.5 ± 2.2 | −162 ± 7 |
| C5aR1-35S2 | 27.8 ± 5.0 | −43.1 ± 0.4 | −93.8 ± 2.2 | −170 ± 7 |
a
No detectable binding observed in two independent experiments.
b
Data from one experiment. Error bounds represent ± S.D.