TABLE 2.
Summary of the capacities, affinities, and thermodynamic parameters of Cu2+, Ni2+, and Ca2+ binding to FMDV capsids measured by ICP-MS, MST, and ITC
| Metal ion | Binding capacitya | Kdb (μM) | ΔHc (cal/mol) | ΔSc (cal/mol/deg) | ΔGc (cal/mol) |
|---|---|---|---|---|---|
| Cu2+ | 7,089 ± 603 | 17 ± 5 | −(1.5 ± 0.3) × 107 | −(5.0 ± 1.0) × 104 | −(1.7 ± 0.4) × 104 |
| Ni2+ | 3,448 ± 445 | 41 ± 4 | −(6.1 ± 2.0) × 105 | −(2.0 ± 0.6) × 103 | −(4.0 ± 1.5) × 103 |
| Ca2+ | 214 ± 39 | 270 ± 18 | −(3.6 ± 2.9) × 105 | −(5.1 ± 3.5) × 102 | −(3.7 ± 0.1) × 103 |
a
Binding capacities refer to the maximal number of metal ions that could tightly bind to the FMDV capsid as determined by ICP-MS.
b
Determined by MST analysis.
c
Determined by ITC analysis. Values are averages and standard deviations obtained from two (binding capacities) or three (Kd, ΔH, ΔS, and ΔG) independent experiments.