Table 1.
ANS binding to CaM and chimeras by fluorescence and ITC
| ANS binding in the absence of salt | ANS binding in the presence of salt | ANS binding in the presence of salt and Orai -CMBD | ||||
|---|---|---|---|---|---|---|
| 30 mM Hepes, pH 7.5, 2 mM Ca 2+ | 30 mM Hepes, pH 7.5, 0.1 M NaCl, 2 mM Ca 2+ | 30 mM Hepes, pH 7.5, 0.1 M NaCl, 2 mM Ca 2+ | ||||
| Protein | ANS enhancement (fold) a | K app (M −1 ) | ANS fold enhancement (fold) a | K app (M −1 ) | ANS fold enhancement (fold) a | K app (M −1 ) |
| CaM | 3.01 ± 0.12 | 2.10 ± 0.11 × 103 | 3.49 ± 0.07 | 3.69 ± 0.08 × 103 | 3.87 ± 0.10 | 3.43 ± 0.65 × 103 |
| CaM(1TnC) | 2.72 ± 0.10 | 9.86 ± 1.24 × 102 | 3.33 ± 0.06 | 1.13 ± 0.04 × 103 | 3.31 ± 0.05 | 1.20 ± 0.08 × 103 |
| CaM(2TnC) | 2.55 ± 0.05 | 1.01 ± 0.07 × 103 | 3.01 ± 0.14 | 1.10 ± 0.01 × 103 | 3.07 ± 0.04 | 9.70 ± 0.31 × 102 |
| CaM(3TnC) | 1.56 ± 0.04 | 6.70 ± 0.51 × 102 | 1.74 ± 0.08 | 8.56 ± 0.21 × 102 | 2.24 ± 0.11 | 1.07 ± 0.10 × 103 |
| CaM(4TnC) | 2.37 ± 0.22 | 1.80 ± 0.05 × 103 | 2.90 ± 0.19 | 2.02 ± 0.03 × 103 | 3.62 ± 0.15 | 2.67 ± 0.24 × 102 |
aThe ANS intensity enhancements were calculated from spectra integration and compared to the corresponding apo proteins in identical experimental conditions.