Skip to main content
. 2021 Apr 1;296:100619. doi: 10.1016/j.jbc.2021.100619

Table 3.

Thermodynamic parameters for Ca2+ binding to nmGCAP2 in the absence (top) and in the presence of 1-mM Mg2+ after fitting ITC data to a two sequential binding site model (mean ± SD, n = 3–4)

nmGCAP2 Ca2+ titration (2-site model)
Apparent dissociation constant KD
Enthalpy change ΔH (kcal/mol)
Entropy change −TΔS (kcal/mol)
KD1 (nM) KD2 (nM) ΔH1 ΔH2 −TΔS1 −TΔS2
No Mg2+
 35.2 ± 10.4 500.5 ± 273.5 −2.1 ± 0.2 −0.05 ± 0.31 −8.1 ± 0.3 −8.6 ± 0.6
With 1-mM Mg2+
 109.3 ± 95.5 2.1 ± 0.6 −2.5 ± 0.2 −2.4 ± 0.5 −7.1 ± 0.7 −5.4 ± 0.6