. Author manuscript; available in PMC: 2010 Dec 14.

Published in final edited form as: Biochemistry. 2009 Dec 15;48(49):11766–11772. doi: 10.1021/bi9014874

Table 2. ΔΔG_C values for CaM-IQ domain complexes.

The indicated K_d ratios were calculated for each reporter construct from the K_d values in Table 1 for binding of the different Ca²⁺⁻ liganded forms of CaM (NC, NC₂, N₂C or N₂C₂). Energy coupling (ΔΔG_C) values were calculated from these K_d ratios according to the relation: ΔΔG_C = RTln(K_d ratio). A positive ΔΔG_C value means that Ca²⁺ binding to the indicated EF hand pair(s) increases the K_d for the complex; a negative value means that Ca²⁺ binding decreases the K_d for the complex.

	NC₂/NC		N₂C₂/NC₂		N₂C/NC		N₂C₂/N₂C		N₂C₂/NC
Construct	K_d Ratio	ΔΔG_C (kJ/mol)	K_d Ratio	ΔΔG_C (kJ/mol)	K_d Ratio	ΔΔG_C (kJ/mol)	K_d Ratio	ΔΔG_C (kJ/mol)	K_d Ratio	ΔΔG_C (kJ/mol)
B_IQ	5.4±0.8	4.1±0.6	0.2±0.03	−3.5±0.5	14.1±1.9	6.5±0.9	0.09±0.012	−5.8±0.8	1.3±0.2	0.7±0.1
B_IQK⁻¹A	2.2±0.4	1.9±0.3	0.1±0.01	−5.5±0.6	5.6±0.9	4.2±0.7	0.04±0.005	−7.8±0.8	0.2±0.09	−3.5±0.6
B_IQA³Q	4.8±1.0	3.8±0.8	0.1±0.03	−4.8±1.1	33.3±4.9	8.6±1.4	0.02±0.003	−9.2±1.7	0.7±0.08	−0.7±0.2
B_IQG⁶K	0.2±0.04	−3.4±0.6	0.2±0.04	−3.6±0.6	1.8±0.3	1.5±0.3	0.03±0.004	−8.5±1.2	0.06±0.008	−7.0±1.1
B_IQTr	0.1±0.02	−5.3±0.7	0.2±0.02	−4.4±0.7	0.8±0.2	−0.4±0.1	0.02±0.004	−9.3±1.5	0.02±0.002	−9.7±1.2
B_IQPEP	0.2±0.03	−4.2±0.5	0.1±0.02	−6.3±1.1	0.8±0.2	−0.5±0.1	0.01±0.003	−10.9±2.1	0.01±0.002	−11.4±1.8

Table 2. ΔΔGC values for CaM-IQ domain complexes.

Table 2. ΔΔG_C values for CaM-IQ domain complexes.