Figure 3.

A, ITC traces for ColN-OBS (residues: 2-18) OmpF binding (filled square) a K_d of 1.4 μm, ΔH of −17.9 kcal/mol, ΔS of −33.4 cal/mol/K, and n of 3.67 peptide/OmpF were determined from this trace, 16.5 μm OmpF was present in the cell, the syringe injected 882 μm ColN^2-19. ColN-OBS shows no binding to OmpF in samples pre-treated with 1 mm ColE9 OBS1 (residues: 2-18) (open circle). 15 μm OmpF and 1 mm ColE9^2-18 was present in the cell, the syringe injected 882 μm ColN^2-19. B, ITC trace for ColN-R (residues: 90-185) OmpF binding (filled square). A K_d of 14 μm, ΔH of −3.8 kcal/mol, ΔS of −9.6 cal/mol/K, and n of 3.82 ColN^90-185/OmpF were determined from this trace, 39 μm OmpF was present in the cell, the syringe injected 1.3 mm ColN^90-185. C, ITC trace for ColN^2-185 OmpF binding (filled square), in the absence of LPS. A K_d of 214 nm, ΔH of −27.7 kcal/mol, ΔS of −62.2 cal/mol/K, and n of 2.69 ColN^2-185/OmpF were determined from this trace, 6 μm OmpF was present in the cell, the syringe injected 60 μm ColN^2-185. All ITC experiments were conducted in 20 mm potassium phosphate, pH 6.5, 1% β-OG.