Skip to main content
. 2023 Jan 13;15(3):mfad003. doi: 10.1093/mtomcs/mfad003

Table 1.

Data from isothermal titration calorimetry experiments

Equilibriuma Complex formed K A (×10−6) K D (μM) ΔH (kcal/mol) ΔS [cal/(mol*K)] ΔG (kcal/mol)
Apo,Zn-HypA + Ni (GoF = 90.2 %)
1 Ni,Zn-HypA 1.11 ± 0.04 0.90 ± 0.04 −0.83 ± 0.02 24.9 −8.23 ± 0.03
UreE2 + Ni (GoF = 57.4 %)
2 Ni-UreE2 3.4 ± 0.1 0.294 ± 0.009 −11.58 ± 0.03 −8.98 −8.91 ± 0.03
UreE2 + Apo,Zn-HypA (GoF = 69.9 %)
3 Apo,Zn-HypA•UreE2 1.19 ± 0.02 0.84 ± 0.01 −6.33 ± 0.01 6.56 −8.28 ± 0.02
UreE2 + Ni,Zn-HypA (GoF = 58.8 %)
1 Ni,Zn-HypA 1.07 ± 0.03 0.94 ± 0.02 −0.83 ± 0.02 24.7 −8.22 ± 0.03
2 Ni-UreE2 2.30 ± 0.02 0.435 ± 0.004 −11.99 ± 0.02 −11.1 −8.67 ± 0.01
3 Apo,Zn-HypA•UreE2 1.28 ± 0.04 0.78 ± 0.02 −5.98 ± 0.05 7.87 −8.33 ± 0.03
4 Ni,Zn-HypA•UreE2 6500 ± 400 0.000154 ± 0.000 009 −12.42 ± 0.02 3.22 −13.38 ± 0.03
5 Ni,Ni,Zn-HypA•UreE2 7.7 ± 0.6 0.13 ± 0.01 −3.31 ± 0.03 −9.40 −9.38 ± 0.08
H102K-UreE2 + Ni,Zn-HypA (GoF = 68.4 %)
1 Ni,Zn-HypA 2.23 ± 0.09 0.45 ± 0.02 −0.787 ± 0.002 26.4 −8.66 ± 0.04
4 Ni,Zn-HypA•H102K-UreE2 16.9 ± 0.9 0.060 ± 0.003 −4.686 ± 0.003 17.3 −9.86 ± 0.05
H152A-UreE2 + Ni (GoF = 47.9 %)
2 Ni-H152A-UreE2 59 ± 5 0.017 ± 0.009 −5.88 ± 0.02 15.8 −10.59 ± 0.08
6 Ni-H152A-UreE4 1.1 ± 0.2 0.909 ± 0.009 −0.80 ± 0.02 25.1 −8.2 ± 0.2
H152A-UreE2 + Ni,Zn-HypA (GoF = 58.4 %)
1 Ni,Zn-HypAb 1.11 0.90 −1.55 ± 0.09 22.5 −8.2
2 Ni-H152A-UreE2b 59 0.017 −6.01 ± 0.07 15.4 −10.59
4 Ni,Zn-HypA•H152A-UreE2 16.0 ± 0.3 0.063 ± 0.001 −2.69 ± 0.01 23.9 −9.82 ± 0.02
6 Ni-H152A-UreE4 1.61 ± 0.04 0.62 ± 0.01 −0.61 ± 0.08 26.3 −8.46 ± 0.02
UreE2 + Ni,Zn-L2*HypA (GoF = 45.5 %)
1 Ni,Zn-L2*HypA 0.0014 ± 0.0001 710 ± 50 −66 ± 3 −206 −4.289 ± 0.007
2 Ni-UreE2 3.6 ± 0.1 0.278 ± 0.008 −11.98 ± 0.07 −8.21 −8.94 ± 0.03
3 Apo,Zn-L2*HypA•UreE2 0.59 ± 0.03 1.69 ± 0.08 −14.06 ± 0.03 −20.8 −7.87 ± 0.05
4 Ni,Zn-L2*HypA•UreE2 19 ± 2 0.053 ± 0.006 −78 ± 3 −228 −9.9 ± 0.1

aThe first column refers to the equilibria indicated in Eqns. 1–8.

bThe values for KA (and KD) were fixed for this fit, as derived from the analogous constants obtained for the single proteins.