Table 1. Spectroscopic Properties of BChls (B850) and Primary Carotenoids in LH2 Complexes Studied Here and Previously.
| Rb. sphaeroides strain (other species) | primary carotenoids (%)a | Nb | NC=C | NC=O | Car S2(0–0)c (nm) RTg | Car S2(0–0)c (nm) 77 K (10 K) | B850 (nm) RT | B850 (nm) 77 K (10 K) | τF (ns)d LDAO (DDM)h | ΦFde (%) LDAO (DDM) | ΦCar→B850f (%) LDAO (DDM) | ref |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ΔcrtC | neurosporene (100) | 9 | 9 | 0 | 492 | 493 | 847 | 853 | 1.33 (0.86) | 10.7 (9.7) | 87 | this work |
| (94) | (21) | |||||||||||
| (G1C) | neurosporene (100) | 9 | 9 | 0 | 492 | (494) | 847 | (854) | 91 | (10) | ||
| ΔcrtA | spheroidene (96) | 10 | 10 | 0 | 511 | 514 | 848 | 851 | 1.38 (1.13) | 11.0 (8.5) | 88 | this work |
| (96) | (21) | |||||||||||
| wild type | spheroidene (100) | 10 | 10 | 0 | 511 | (515) | 848 | (852) | 93 | (10) | ||
| 1.8i | (29) | |||||||||||
| 1.0 | (30) | |||||||||||
| 0.98 | 9.9 | (31) | ||||||||||
| 0.93 | (32) | |||||||||||
| ΔcrtI::crtIPaΔcrtC | lycopene (91) | 11 | 11 | 0 | 524 | 527 | 848 | 854 | 1.1 (0.76) | 8.5 (7.5) | 66 | this work |
| (64) | (21) | |||||||||||
| (DPF240[pERWI2]) | lycopene | 11 | 11 | 0 | 526 | ∼55 | (33) | |||||
| ΔcrtI::crtIPa ΔcrtD | rhodopin (26), lycopene (34), MeO/OH-lycopenes (36) | 11 | 11 | 0 | 524 | 529 | 849 | 856 | 1.1 (0.8) | 8.1 (6.8) | 65 | this work |
| (62) | (21) | |||||||||||
| (Rps. acidophila 10050) | rhodopin glucoside (100) | 11 | 11 | 0 | 524 | (529) | 856 | (868) | 54 | (10) | ||
| 1.0 | (32, 34) | |||||||||||
| ΔcrtI:crtIPa (PS)j | spirilloxanthin (71) | 13 | 13 | 0 | 0.89 (0.77) | 5.5 (6.2) | 46 | this work | ||||
| (39) | (21) | |||||||||||
| 555 | 556 | 849 | 852 | 41 | (24) | |||||||
| Δ:crtIPa (SA)k | diketospirilloxanthin (62) | 15 | 13 | 2 | 0.74 (0.71) | 4.8 (5.7) | 41 | this work | ||||
| Ketospirilloxanthin (16) | 14 | 13 | 1 | (35) | (21) | |||||||
| n.r.l | 849 | 853 | 42 | (24) |
a
From Chi et al.21
b
Total number of conjugated double bonds (N = NC=C + NC=O).
c
(0–0) S0 → S2 absorption band.
d
B850 excited-state lifetime from fluorescence decay.
e
B850 fluorescence quantum yield.
f
Carotenoid-to-BChl a energy transfer efficiency from excitation vs absorptance (1–T) spectra.
g
Room temperature.
h
LDAO vs DDM preparations.
i
At 6 K.
j
Photosynthetically (anaerobically) grown.
k
Semiaerobically grown.
l
Not resolved.