Table 1.
Binding constants of synthetic hosts, antibodies, proteins and enzymes with neutral organic compounds.
| Host type | Guest type | Mean log Ka |
Standard deviation[a] |
−ΔG [kcal mol−1] |
|---|---|---|---|---|
| cyclodextrin | organic molecule |
2.5 | 1.1 | 3.5 ± 1.4 |
| organic host[b] |
organic molecule |
3.4 | 1.6 | 4.6 ± 2.1 |
| catalytic antibody |
substrate | 3.5 | 1.0 | 4.8 ± 1.3 |
| enzyme | substrate | 3.7 | 1.3 | 5.1 ± 1.7 |
| albumin | organic molecule |
4.6 | 0.9 | 6.3 ± 1.3 |
| catalytic antibody |
transition state |
6.6 | 2.0 | 9.0 ± 2.7 |
| receptor | drug | 7.3 | 1.5 | 9.5 ± 2.1 |
| antibody | antigen | 8.1 | 2.0 | 11.1 ± 2.7 |
| enzyme | inhibitor | 8.6 | 2.1 | 11.7 ± 2.8 |
| enzyme | transition state |
16.0 | 4.0 | 21.9 ± 5.4 |
[a]
In units of log Ka; 68% of cases fall within one standard deviation of the mean value, 95% within two standard deviations for a normal distribution.
[b]
In aqueous solvent.