Table 2. Dissociation Constant Values for Three Different Complexes Calculated by Fluorescence Spectroscopy at Different Salt Concentrationsa.
Kd (μM) ligand–protein |
|||
---|---|---|---|
NaCl (mM) | SPD304/TNF-α | PABA/tryspin | RRLIF/cyclinA2 |
50 | 5.42 ± 0.35 | 4.32 ± 0.31 | N.D. |
100 | 5.53 ± 0.51 | 4.12 ± 0.42 | 24.36 ± 1.25 |
250 | 5.71 ± 0.32 | 6.64 ± 0.35 | 17.45 ± 0.98 |
500 | 5.92 ± 0.42 | 8.58 ± 0.49 | 8.47 ± 0.62 |
Experiments performed in 10 mM citrate phosphate (pH 6.5) containing 5% DMSO, 50 mM Tris-HCl pH 8.0 containing 0.01% monothioglycerol, and 20 mM phosphate buffer (pH 7.4) containing 0.1% PEG6000, respectively, at 25 °C. The mean values of three independent measurements are presented. N.D.: not determined.