Table 2.
Marcus intrinsic barriers (kcal/mol)a.
| Enzyme | ΔG0 solution | ΔG0 active site | ΔΔGint |
|---|---|---|---|
| Ketosteroid isomerase | 13 | 9.5 | −3.5 |
| Proline racemase | 10.5 | 5.1 | −5.4 |
| Tryptophan indole-lyase | 10.4b | 12.8 | +2.4 |
| Tyrosine phenol-lyase | 10.4b | 15.5 | +5.1 |
| Aspartate aminotransferase | 10.4b | 11.5 | +1.1 |
| Dialkylglycine decarboxylase | 10.4b | 11.3 | +0.9 |
a
Intrinsic barriers to reaction based on Marcus theory, without including any work terms since the juxtaposed active site base catalytst and substrate react in a unimolecular step in the absence of bulk solvent. Calculation details in Supplementary Material.
b
Calculated intrinsic barrier for Gly-pyridoxal aldimine in water.