Table 1.

Association constants for various metal binding equilibrium models for ^C96RIDC-1₄ determined through competitive Fura-2 titrations (pH 7, 295 K). The total free energies for metal binding correspond to the free energy sums of individual equilibria (times their multiplicity) for every model. Corresponding titrations and fits are shown in Figure 4b (Zn²⁺), Figure 7 (Cu²⁺ and Ni²⁺) and Figure S11 (Co²⁺). Numbers in parentheses correspond to standard deviation in the last reported significant figure, were obtained through DynaFit, and do not include any experimental errors.

Total metal equivalents	Number of Consecutive Binding Equilibria	Kd1 (M)	Kd2 (M)	Kd3 (M)	Kd4 (M)	Total -ΔG for metal binding (kJ mol−1)
4 Zn2+	2	5.2(4) × 10−10	4.3(2) × 10−8			189
	4	1.3(3) × 10−9	5.3(7) × 10−10	3.3(8) × 10−8	5.8(8) × 10−8	186
2 Cu2+	1	1.0(1) × 10−12				136
	2	2.5(3) × 10−13	1.4(1) × 10−12			138
2 Ni2+	1	8.0(9) × 10−9				92
	2	9.0(1) × 10−10	4.9(5) × 10−9			93
1 Co2+	1	9(4) × 10−7				34