Table 1 Thermodynamic parameters of IKKα or IKKβ binding to YDDΦXΦ peptides

From: Molecular mechanism of IKK catalytic dimer docking to NF-κB substrates

interaction

N

KD (μM)

ΔH (kcal/mol)

TΔS (kcal/mol)

ΔG (kcal/mol)

IKKα / IκBα pep wt

0.63

7.7 (6.5, 9.4)

−14.2 (−15.5, −13.2)

−7.23

−6.97

IKKα / IκBα pep C308L

0.65

0.42 (0.33, 0.55)

−13.7 (−14.1, −13.4)

−5.01

−8.69

IKKα / pY-IκBα pep

N.D.

N.D.

N.D.

N.D.

N.D.

IKKβ / IκBα pep wt

0.63

40 (35, 46)

−16.3 (−19.3, −14.2)

−10.3

−6.00

IKKβ / IκBα pep C308L

0.66

2.4 (1.7, 3.1)

−11.5 (−12.1, −10.8)

−3.83

−7.67

IKKα / p100 pep

0.60*

12** (3.5, 18)

−13.4** (−17.2, −8.30)

−6.69

−6.71

IKKα / IRF7 pep

N.D.

N.D.

N.D.

N.D.

N.D.

  1. All ITC experiments were performed at 25 °C. The data were fitted to a 1:1 binding model. N refers to the binding stoichiometry of IKKα/β: pep. Data were processed using the NITPIC software60. For each interaction, the thermodynamic parameters were derived from the global fitting of two independent titration curves (n = 2) using the SEDPHAT software61. For the best-fit values of KD and ΔH, a confidence interval at 68.3% probability (one SD assuming a Gaussian error distribution) was calculated (in brackets) using error surfaces prescribed by F-statistics.
  2. *value constrained during fitting.
  3. **broad confidence intervals correspond to poor convergence, therefore, for this titration fitted values should be considered as estimates.
  4. N.D. not determined.
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