Table 6.
The calculated excitation energy (nm) of the absorbing state for the WT bovine Rh and its E122Q and E113Q mutants at protein geometries in the absence (QM-none) and presence (QM/MM) of protein environments (QM region: R1; basis set: 6-31G*)a
| Structure [Experiment] |
WT Rh [500 (0)] |
E122Q [480 (-20)] |
E113Q[384 (-116)] |
|||
|---|---|---|---|---|---|---|
| Retinal Protonation |
PSBR |
PSBR |
SBR |
|||
| QM Method | QM-none | QM/MM | QM-none | QM/MM | QM-none | QM/MM |
| TD-B3LYP | 560 (0) | 503 (0) | 566 (6) | 492 (-11) | 398 (-162) | 409 (-94) |
| DDCI2+Q(12/12) | 527 (0) | 435 (0) | 522 (-5) | 427 (-8) | 310 (-217) | 320 (-115) |
| SORCI+Q(6/6) | 616 (0) | 495 (0) | 586 (-30) | 462 (-33) | 327 (-289) | 330 (-165) |
| MRCISD+Q(6/6) | 626 (0) | 499 (0) | 584 (-42) | 490 (-9) | 323 (-303) | 322 (-177) |
a
Numbers (nm) in parentheses are spectral shifts relative to the WT bovine Rh. The calculated QM and QM/MM shifts are relative to the QM-none and QM/MM results of WT Rh.