Table 1. Best fit parameters for ITC measurements of IlsA binding to ferritinsa.
Protein 1 | Protein 2 | n | K (M−1) | ΔH0 (kJ/mol) | ΔG0 (kJ/mol)b | ΔS0 (J/(mol.K))c |
Holo-IlsA | HuHF | 25.21±2.62 | (1.86±0.99) ×106 | −4.11±0.11 | −35.78±1.32 | 106.24±4.44 |
Holo-IlsA | HuLF | 23.88±0.1 | (8.36±0.24) ×105 | −8.71±3.15 | −33.80±0.07 | 84.16±10.56 |
Holo-IlsA | HuH/LF | 23.79±0.89 | (1.08±0.21) ×106 | −8.72±2.47 | −34.44±0.48 | 86.26±8.44 |
Holo-IlsA | MoHF | 24.94±1.73 | (2.07±0.66) ×106 | −3.35±0.32 | −36.05±0.79 | 109.68±2.85 |
The reported thermodynamic quantities are apparent values and include the contributions to the overall equilibrium from ferritin and buffer species in different states of protonation.
Standard errors from replicate determinations are indicated.
Calculated from ΔG 0 = −RTlnK.
Calculated from ΔS 0 = (ΔH°−ΔG°)/T.
HuHF, recombinant human H-chain ferritin; HuLF, recombinant human L-chain ferritin; HuH/LF, recombinant heteropolymer ferritin of 21H-chains and 4L-chains; MoHF, recombinant mouse H-chain ferritin. All experiments were repeated two to four times.