Table 1 Results of ITC experiments titrating the ATD dimer with various ligands

N-substituent volume (ų)

(n/a)

(n/a)

0.97

33.74

50.54

50.33

67.35

67.35

67.13

n ^{pH 7.6}

1.0 ± 0.01

0.98 ± 0.01

0.98 ± 0.02

1.00 ± 0.01

1.0 ± 0.01

1.0 ± 0.01

0.95 ± 0.01

0.99 ± 0.02

1.0 ± 0.02

n ^{pH 6.5}

0.97 ± 0.01

–

0.98 ± 0.01

0.98 ± 0.01

1.0 ± 0.01

1.0 ± 0.01

1.0 ± 0.01

1.00 ± 0.02

0.99 ± 0.02

K_D^{pH 7.6} (nM)

226 ± 15

255 ± 11

147 ± 5.0

66.3 ± 3.2

129 ± 9.3

175 ± 5.6

121 ± 5.1

331 ± 29

305 ± 18

K_D^{pH 6.5} (nM)

249 ± 16

–

170 ± 4.8

70.7 ± 2.0

116 ± 2.2

186 ± 11

78 ± 3.0

171 ± 6.6

147 ± 5.6

ΔH^{pH 7.6} (kcal mol⁻¹)

−1.53 × 10⁴ ± 346

−1.48 × 10⁴ ± 265

−2.37 × 10⁴ ± 457

−2.28 × 10⁴ ± 834

−1.94 × 10⁴ ± 809

−2.38 × 10⁴ ± 708

−2.16 × 10⁴ ± 944

−2.79 × 10⁴ ± 765

−2.12 × 10⁴ ± 568

ΔH^{pH 6.5} (kcal mol⁻¹)

−1.70 × 10⁴ ± 982

–

−2.24 × 10⁴ ± 483

−2.11 × 10⁴ ± 1140

−1.96 × 10⁴ ± 146

−2.09 × 10⁴ ± 568

−2.22 × 10⁴ ± 807

−2.03 × 10⁴ ± 1430

−1.75 × 10⁴ ± 941

TΔS^{pH 7.6} (kcal mol⁻¹)

−6.10 × 10³ ± 308

−5.64 × 10⁴ ± 264

−1.42 × 10³ ± 447

−1.28 × 10⁴ ± 866

−9.87 × 10³ ± 804

−1.41 × 10⁴ ± 536

−1.19 × 10⁴ ± 914

−1.89 × 10⁴ ± 804

−1.22 × 10⁴ ± 544

TΔS^{pH 6.5} (kcal mol⁻¹)

−7.84 × 10³ ± 960

–

−1.30 × 10³ ± 500

−1.12 × 10⁴ ± 1140

−9.92 × 10³ ± 132

−1.16 × 10⁴ ± 604

−1.23 × 10⁴ ± 811

−1.09 × 10⁴ ± 1440

−8.00 × 10³ ± 919

pH-boost

0.91 ± 0.066

–

0.86 ± 0.030

0.94 ± 0.047

1.11 ± 0.081

0.94 ± 0.034

1.55 ± 0.067

1.93 ± 0.168

2.08 ± 0.125