Table 1.

Thermodynamic parameters for TolB binding ColE9 and Pal obtained by isothermal titration calorimetry at 20°C

Protein	ΔH, kcal/mol	TΔS, kcal/mol	ΔG, kcal/mol	Kd, μM	n
ColE9	−15.7 (±0.1)	−7.7 (±0.1)	−8.0 (±0.1)	1.00 (±0.09)	0.99 (±0.05)
ColE9 Tpep32–47	−14.7 (±0.1)	−6.6 (±0.1)	−8.1 (±0.0)	0.92 (±0.03)	1.07 (±0.03)
Pal	−7.1 (±0.0)	2.7 (±0.0)	−9.8 (±0.0)	0.047 (±0.002)	1.06 (±0.04)

Data generated from the titration of ColE9, ColE9 T_pep32–47, or Pal into TolB. Errors shown are from duplicate measurements. Experiments were conducted in 50 mM potassium phosphate buffer (pH 7.5) containing 50 mM NaCl and 10 mM EDTA. For further details, see Supporting Materials and Methods.