Table 2.

Dissociation Constants^a for Binding of Ca²⁺ to S100A4

protein	MIIA1851–1960	EF1 (μM)	EF2 (μM)
wt-S100A4b	+	4.26 ± 0.04	0.44 ± 0.04
wt-S100A4c	−	>500	7.6 ± 0.4
sc-S100A4–5b	+	1.65 ± 0.05	0.74 ± 0.11
sc-S100A4–10b	+	3.20 ± 0.30	1.10 ± 0.18
sc-S100A4–5M1b	+	169 ± 23	0.51 ± 0.05
sc-S100A4–5M1c	−	366 ± 93	1.83 ± 0.34
sc-S100A4–5M2b	+	205 ± 41	0.24 ± 0.03
sc-S100A4–5M2c	−	>500	0.75 ± 0.21
sc-S100A4–10M1b	+	244 ± 46	0.43 ± 0.06
sc-S100A4–10M1c	−	223 ± 26	1.46 ± 0.31
sc-S100A4–10M2b	+	>500	0.92 ± 0.30
sc-S100A4–10M2c	−	>500	1.26 ± 0.12

^aValues represent the average from two or three independent experiments.

^bMacroscopic Ca²⁺ binding constants determined for 12.5 μM S100A4 dimer in the presence of 100 μM MIIA^1851–1960 monomer.

^cMacroscopic Ca²⁺ binding constants determined for 12.5 μM S100A4 dimer in the absence of target.