TABLE 3.

ITC fitting parameters for the binding of InsP₃R-(1-587) to various molecules

Molecule	Kd	ΔH	ΔS
	μm	kcal mol−1	cal mol−1 K−1
Mg2+-bound CaBP1	30 ± 3	−1.55 ± 0.1	15.9
Ca2+-bound CaBP1	3 ± 0.3	−1.96 ± 0.2	17.9
Mg2+-bound CaBP1-C	30 ± 3	−0.36 ± 0.1	21.7
Ca2+-bound CaBP1-C	2.5 ± 0.3	−1.92 ± 0.2	19.3
Ca2+-bound CaBP1-C (ΔL132)	3.6 ± 0.3	−2.22 ± 0.2	17.7
Ca2+-bound CaBP1-C (H134E)	5.6 ± 0.5	−2.35 ± 0.2	16.5
Ca2+-bound CaBP1-C (V148A)	5.1 ± 0.4	−2.03 ± 0.2	17.3
Mg2+-bound CaBP1-N	-a	-	-
Ca2+-bound CaBP1-N	-	-	-
Apo-CaM	-	-	-
Ca2+-bound CaM	-	-	-
InsP3	1.9 ± 0.2	−16 ± 0.4	−27.5
InsP3 (+CaBP1)	1.6 ± 0.2	−15 ± 0.6	−24.7

^aIndicates no detectable binding.