Table 3. Thermodynamic parameters and binding data for the interaction of the homo- and heteroglycopeptide dendrimers with LecA a .
| Ligand | n Gal | n b | ΔH [kcal mol–1] | –TΔS [kcal mol–1] | ΔG [kcal mol–1] | K D [nM] | r.p./nGal d |
| NPG c | 1 | 0.91 ± 0.03 | –10.6 ± 0.45 | 4.0 | 6.5 | 16 000 ± 500 | 0.2 |
| GalAG0 | 1 | 0.65 ± 0.02 | –17.8 ± 0.3 | 10.2 | –7.5 | 3000 ± 50 | 1 |
| Het1G1-Cys | 1 | 1.17 ± 0.04 | –7.83 ± 0.26 | 0.85 | –7.0 | 7800 ± 1200 | 0.4 |
| Het2G1-Cys | 1 | 1.37 ± 0.09 | –7.36 ± 0.093 | 0.35 | –7.0 | 7340 ± 300 | 0.4 |
| GalAG1 | 2 | 0.30 ± 0.003 | –29 ± 0.5 | 19.3 | –9.7 | 83 ± 12 | 18 |
| GalAG1-Cys | 2 | 0.66 ± 0.06 | –14.2 ± 0.05 | 4.9 | –9.3 | 164 ± 0.2 | 9 |
| Het1G2 | 2 | 0.44 ± 0.01 | –23.0 ± 0.14 | 13.3 | –9.7 | 75 ± 17 | 20 |
| Het2G2 | 2 | 0.36 ± 0.03 | –25.0 ± 0.15 | 15.2 | –9.7 | 75 ± 18 | 20 |
| GalAG2 | 4 | 0.14 ± 0.01 | –68.6 ± 1.10 | 57 | –11.7 | 2.5 ± 0.1 | 300 |
| GalAG2x | 4 | 0.21 ± 0.02 | –32.4 ± 0.47 | 22 | –10.4 | 23 ± 0.3 | 32 |
| GalBG0 | 1 | 0.71 ± 0.01 | –14 ± 0.04 | 7.8 | –6.0 | 37 000 ± 800 | 1 |
| GalBG1 | 2 | 0.37 ± 0.02 | –20 ± 0.1 | 12 | –8.2 | 1060 ± 160 | 18 |
| GalBG1-Cys | 2 | 0.53 ± 0.06 | –13.9 ± 0.82 | 5.4 | –8.5 | 600 ± 1 | 31 |
| Het3G2 | 2 | 0.25 ± 0.02 | –30.3 ± 0.40 | 21 | –9.0 | 255 ± 14 | 73 |
| Het4G2 | 2 | 0.15 ± 0.00 | –42.0 ± 0.21 | 36 | –9.4 | 120 ± 2 | 153 |
| Het7G2 | 2 | 0.25 ± 0.02 | –28.4 ± 0.69 | 20 | –8.8 | 340 ± 70 | 55 |
| Het8G2 | 2 | 0.25 ± 0.00 | –25.5 ± 0.25 | 16.4 | –9.0 | 250 ± 16 | 75 |
| GalBG2 | 4 | 0.18 ± 0.02 | –43 ± 1 | 33 | –10.1 | 40 ± 1 | 230 |
aThermodynamic parameters and dissociation constants KD are reported as an average of two independent runs from ITC in 20 mM Tris, 100 mM NaCl, 100 μM CaCl2, pH = 7.5. Isothermal Titration Calorimetry (ITC) data are for LecA binding. Titration concentrations for Ligand/LecA are indicated in brackets: NPG (3.0 mM/0.3 mM), GalAG0 (0.5 mM/0.0516 mM), Het1G1-Cys (1.2 mM/0.051 mM), Het2G1-Cys (0.57 mM/0.05 mM), GalAG1 (0.25 mM/0.0486 mM), GalAG1-Cys (0.255 mM/0.05 mM), Het1G2 (0.25 mM/0.05 mM), Het2G2 (0.25 mM/0.05 mM), GalAG2 (0.03 mM/0.018 mM), GalAG2x (0.0909 mM/0.0166 mM), GalBG0 (1.0 mM/0.091 mM), GalBG1 (0.25 mM/0.049 mM), GalBG1-Cys (0.4 mM/0.0526 mM), Het3G2 (0.5 mM/0.1 mM), Het4G2 (0.1 mM/0.05 mM), Het7G2 (0.175 mM/0.05 mM), Het8G2 (0.175 mM/0.05 mM), GalBG2 (0.03 mM/0.08 mM).
b n defined the stoichiometry of the binding.
cNPG is 4-nitrophenyl-β-d-galactopyranoside (reference used in the ITC measurements with LecA), (3 mM/0.3 mM, Ligand/LecA).
dRelative potency per galactoside. r.p./nGal = KD(GalAG0 or GalBG0)/KD(ligand)/nGal. nGal = number of copies of galactosides in the glycopeptide dendrimer. See ESI Fig. S108 for ITC plots.