Table 2. Correlated Fit of the UV–vis Absorption and MCD spectra of Cyt P450cam Q360P.
No. | MCD | UV–vis | Calculated (average) | Assignmenta | Polarization from MCD | |||
---|---|---|---|---|---|---|---|---|
Energy, cm-1 | Δε | Energy, cm-1 | ε | |||||
1 | 15222 | 8 | 15223 | 3512 | NA | |||
2 | 15909 | 31 | 15790 | 4160 | 12480 |
|
x,y | |
3 | 16919 | -23 | 16800 | 5300 | 14721 | , A2u<81> → dxz | x,y | |
4 | 17881 | -32 | 17700 | 5402 | 16786 | CT(S,π) P → Fe CT | x,y,z | |
5 | 18604 | -47 | 18480 | 8707 | 19582 | Q-band | x,y | |
6 | 19539 | 37 | 19410 | 10786 | 19789 | x,y | ||
7 | 20539 | 83 | 20539 | 13578 | 25761 | π → π*(1), A2u<81> → dx2y2 | x,y | |
8 | 21807 | 112 | 21807 | 15193 | 27291 | , π → π* (3) | ||
9 | 22685 | 28 | 22607 | 14777 | 28089 | π → π* (3) | ||
10 | 23731 | -111 | 23558 | 28506 | 28367 | Soret, π → π* (3), πpor +πsc(por) → dz2 | x,y | |
11 | 24859 | 141 | 25013 | 78151 | 30636 | Soret, , πpor +/σsc(por) → dz2, σpor_dx2-y2 → dxy | x,y | |
12 | 25618 | -97 | 26492 | 52849 | 31099 | Soret, , CT(S,σ) | x,y | |
13 | 28570 | -179 | 28438 | 44742 | 31335 | CT(S,σ), , , , , π/σsc(por)+πpor → dxy | x,y,z | |
14 | 31042 | 47 | 31042 | 20066 | NA |
Note that σpor and πpor are distorted MOs that can only be classified as σ and π bonding porphyrin (por) orbitals, respectively. In some transitions, the propionate side chains (sc) of heme b are involved.