Table 1.
Values of Em(PA), Em(PB) (in mV), PA•+/PB•+ ratios, and spin-density distributions in the PSI protein (in %)
| (Factor) |
Em shift (versus reference) |
Charge |
Spin |
||||
|---|---|---|---|---|---|---|---|
| PA | PB | PA•+ | PB•+ | PA | PB | ||
| Wild-type | 29∗ | 27 | 27.9 | 72.1 | 22.4 | 77.6 | |
| (1) | T743V [H-bond] | 20∗ | 28 | 32.2 | 67.8 | 26.9 | 73.1 |
| (2) | CH3COO− deleted [Epimer] | 32.2 | 67.8 | 29.7 | 70.3 | ||
| (3) | Δ(Arg-A750/Ser-B734) [PsaA/PsaB pair] | 30.6 | 69.4 | 25.0 | 75.0 | ||
| (4) | Δ(A−1A/A−1B) [Cofactor] | 24.0 | 76.0 | 18.7 | 81.3 | ||
The symbol Δ stands for deletion of atomic charges of the residues/groups.
∗
Because Em(Chla′) in the reference model system is unknown, only the Em shift was calculated. An actual Em(Chla′) may be higher than Em(Chla) because Chla′ is thermodynamically less stable than Chla (9).