Table 1.
The energy profile (in kcal/mol) obtained for cluster modeling of pathway (a) and (b) (pro(R)). Two variants of the benzyl radical attack on the fumarate are considered (a) the attack on the distal carbon atom and (b) the attack on the proximal one (with respect to the Cys493). All energy differences were calculated with respect to ES.
| Species | ∆E(B3LYP+D2/6-31g(dp)) | ∆E B3LYP+D2/6-311+g(2d,2p)+ZPE + Solvent Correction | ∆E B3LYP+D2/6-311+g(2d,2p)+Thermal Energy + Solvent Correction | ∆E B3LYP+D2/6-311+g(2d,2p)+G + Solvent Correction |
|---|---|---|---|---|
| ES | 0.00 | 0.00 | 0.00 | 0.00 |
| TS1 | 20.01 | 14.55 | 13.13 | 18.42 |
| I1 | 8.53 | 5.18 | 5.05 | 5.71 |
| Pathway (a) | ||||
| TS2a | 11.35 | 10.09 | 9.08 | 13.63 |
| I2a | −7.28 | −6.20 | −7.29 | −2.82 |
| TS3a | 14.41 | 10.94 | 9.26 | 15.18 |
| Pa | −14.38 | −11.58 | −12.94 | −7.71 |
| Pathway (b) | ||||
| TS2b | 14.40 | 11.69 | 10.50 | 15.59 |
| I2b | −4.34 | −4.65 | −5.99 | −0.12 |
| TS3b | 53.03 | 46.55 | 44.63 | 52.53 |
| Pb | −8.33 | −6.14 | −7.98 | −1.03 |