Table 2.
Photochemical properties of light-driven outward proton pump rhodopsins.
| Opsin type | λmax (nm) | Retinal configuration | M-decay rate constant | pKa value |
|---|---|---|---|---|
| N2098R | 550 | All-trans (predominant) | Approx. 0.016 ms−1 |
Below 2.0 (Asp74) Approx. 10.7 (Lys204) |
| BR | 57024 |
All-trans (apprx. 50%)27 13-cis (approx. 50%)27 |
Approx. 0.25 ms−135 |
Approx. 2.6 (Asp85)29 Approx. 13.3 (Lys216)32 |
| PR (GPR) | 5206 | All-trans (predominant)25 | Approx. 4 ms−125 |
Approx. 7.9 (Asp97)30 Approx. 11.3 (Lys227)33 |
| PR (BPR) | 49042 | N.D. | N.D. |
Approx. 6.2 and 7.9 (Asp97)31 N.D. (Lys227) |
| GR | 54416 | All-trans (predominant)15,26 |
Approx. 2.3 ms−115, Approx. 1 ms−136 |
Approx. 5.9 (Asp121)16 Approx. 9.2 (Lys257)16 |