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Table 2 Thermodynamic ITC data for CAPs and reference ligands Wrf and Dgly

From: Synthetic cationic antimicrobial peptides bind with their hydrophobic parts to drug site II of human serum albumin

Ligand Kdc,† nd, ‡ ΔGe,§ ΔHf, # TΔSg, $
CAP 1 - - - - -
CAP 2 a 23 ± 8 0.67 ± 0.07 -6.32 ± 0.18 -3.7 ± 0.5 2.6 ± 0.7
CAP 3 a 22 ± 9 (99 ± 6)b 0.77 ± 0.07 (0.36 ± 0.03)b -6.36 ± 0.19 (-5.46 ± 0.04)b -2.8 ± 0.4 (-16.7 ± 1.3)b 3.5 ± 0.6 (-11.2 ± 1.4)b
CAP 4 a 25 ± 9 0.57 ± 0.08 -6.28 ± 0.19 -5.2 ± 1.0 1.1 ± 1.1
CAP 5 b (100 ± 13) (1.01 ± 0.05) (-5.46 ± 0.07) (-3.0 ± 0.2) (2.5 ± 0.3)
Wrf b (site I) 9 ± 4 (28 ± 4) 1.15 ± 0.04 (1.02 ± 0.02) -6.87 ± 0.19 (-6.21 ± 0.07) -2.4 ± 0.1 (-3.3 ± 0.1) 4.4 ± 0.3 (2. ± 0.)
Dgly b (site II) 11 ± 4 (40 ± 2) 1.08 ± 0.05 (1.16 ± 0.01) -6.78 ± 0.20 (-6.00 ± 0.02) -4.5 ± 0.3 (-5.5 ± 0.1) 2.3 ± 0.5 (0.5 ± 0.1)
  1. CSC 5300 Nano-Isothermal Titration Calorimeter III data, values obtained by MicroCal iTC200 presented in parenthesis. (Kd in μM, ΔG, ΔH and TΔS in kcal/mol, n denotes the stoichiometric ratio).
  2. aThree parallels.
  3. bTwo parallels.
  4. cError limits taken as the average of the maximal difference between Kd and calculated Kd ± error limits 95% confidence interval from Ka CSC 5300 Nano-Isothermal Titration Calorimeter III, default error calculations based on least square fit and χ2 with iTC200.
  5. dError limits are the averages of ± 95% confidence interval of the parallels CSC 5300 Nano-Isothermal Titration Calorimeter III, default error calculations based on least square fit and χ2 with iTC200.
  6. eError limits taken as the average of the maximal difference between ΔG and calculated of ΔG ± error limits 95% confidence interval from Ka CSC 5300 Nano-Isothermal Titration Calorimeter III, default error calculations based on least square fit and χ2 with iTC200.
  7. f Error limits are the averages of ± 95% confidence interval of the parallels CSC 5300 Nano-Isothermal Titration Calorimeter III, default error calculations based on least square fit and χ2 with iTC200.
  8. gError limits by cumulative addition of error limits of ΔG and ΔH.
  9. Deviation between parallels < 16%, except Wrf with 39%. Deviation between parallels < 21%. § Deviation between parallels < 3%. # Deviation between parallels < 12%. $Deviation between parallels < 20%, except CAP 4 with 63%. The symbol “-“denotes no measured binding.