Table 1

Observed thermodynamic parameters of EZA binding to hCA XIII in phosphate and TRIS buffers are listed as a function of pH as determined by ITC at 25°C
pH Kb_obs, M-1 ΔbGobs, kJ/mol ΔbHobs, kJ/mol TΔbSobs, kJ/mol ΔbSobs, kJ/(mol × K)
EZA - hCA XIII binding in phosphate buffer
6.0 1.70 × 107 −41.27 −11.36 29.91 0.10
7.0 1.17 × 108 −46.05 −17.84 28.21 0.09
8.0 4.96 × 108 −49.63 −37.76 11.87 0.04
9.0 3.33 × 108 −48.65 −66.48 −17.84 −0.06
EZA - hCA XIII binding in TRIS buffer
6.0 5.95 × 106 −38.67 −58.20 −19.53 −0.07
7.0 2.10 × 108 −47.50 −59.71 −12.20 −0.04
8.0 8.69 × 108 −51.02 −48.79 2.24 0.01
9.0 2.27 × 108 −47.70 −33.36 14.33 0.05

Both the observed binding constants and enthalpies were highly pH and buffer-dependent. Standard deviations are below 10% for all parameters measured in kJ/mol.

Baranauskienė and Matulis

Baranauskienė and Matulis BMC Biophysics 2012 5:12   doi:10.1186/2046-1682-5-12

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