Bacteriophytochrome-Dependent Regulation of Light-Harvesting Complexes in Rhodopseudomonas palustris Anaerobic Cultures

2010 ◽  
Vol 61 (5) ◽  
pp. 429-434 ◽  
Author(s):  
Meng Li ◽  
Stephan Noll ◽  
J. Thomas Beatty
2009 ◽  
Vol 97 (11) ◽  
pp. 3019-3028 ◽  
Author(s):  
Vladimíra Moulisová ◽  
Larry Luer ◽  
Sajjad Hoseinkhani ◽  
Tatas H.P. Brotosudarmo ◽  
Aaron M. Collins ◽  
...  

2011 ◽  
Vol 440 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Tatas H. P. Brotosudarmo ◽  
Aaron M. Collins ◽  
Andrew Gall ◽  
Aleksander W. Roszak ◽  
Alastair T. Gardiner ◽  
...  

The differing composition of LH2 (peripheral light-harvesting) complexes present in Rhodopseudomonas palustris 2.1.6 have been investigated when cells are grown under progressively decreasing light intensity. Detailed analysis of their absorption spectra reveals that there must be more than two types of LH2 complexes present. Purified HL (high-light) and LL (low-light) LH2 complexes have mixed apoprotein compositions. The HL complexes contain PucABa and PucABb apoproteins. The LL complexes contain PucABa, PucABd and PucBb-only apoproteins. This mixed apoprotein composition can explain their resonance Raman spectra. Crystallographic studies and molecular sieve chromatography suggest that both the HL and the LL complexes are nonameric. Furthermore, the electron-density maps do not support the existence of an additional Bchl (bacteriochlorophyll) molecule; rather the density is attributed to the N-termini of the α-polypeptide.


2014 ◽  
Vol 121 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Masahiko Taniguchi ◽  
Sarah Henry ◽  
Richard J. Cogdell ◽  
Jonathan S. Lindsey

2016 ◽  
Vol 78 (4-2) ◽  
Author(s):  
Monika Nur Utami Prihastyanti ◽  
Heriyanto Heriyanto ◽  
Tatas Hardo Panintingjati Brotosudarmo

Purple photosynthetic light–harvesting (LH2) is an attractive complex module for assembling hybrid nanostructures that feature energy transfer. LH2 has a broad absorption spectrum range from ultraviolet (UV) to near-infra red (NIR) region. Bacteriochlorophyll a molecules absorb at 320 nm to 400 nm (Soret band), 585 nm (Qx) and at NIR region (B800 and B850 bands), while carotenoid absorption bands span from 400 nm to 550 nm. LH2 has to be extracted from its native lipid bilayer membrane and placed in suitable matrix that less mobile and better adherent than the native lipid environment to determine its function. Previous results on pigment ratio determination in different strains of purple photosynthetic bacteria suggested a variation during initial log phase and late log phase. In this experiment, the goal is to reveal the behavior of pigment ratio in LH2 of Rhodopseudomonas palustris during irradiation of certain intensity of light. Photostability assay of LH2 from Rhodopseudomonas palustris in n-dodecyl-β-D-maltoside or DDM was determined under continuous illumination (3 000 μmol·m–2·s–1) for 300 min at room temperature by recording the absorption spectra. Degradation was observed in B850 and B800 at about 67 % and 64 %, respectively, as well as blue shift in B850. Initial pigments isolated from LH2 suggested a mixture of carotenoids and bacteriochlorophylls which was determined further using a high-performance liquid chromatography (HPLC).


2021 ◽  
Vol 3 (2) ◽  
pp. 262-271
Author(s):  
Pablo Reséndiz-Vázquez ◽  
Ricardo Román-Ancheyta ◽  
Roberto León-Montiel

Transport phenomena in photosynthetic systems have attracted a great deal of attention due to their potential role in devising novel photovoltaic materials. In particular, energy transport in light-harvesting complexes is considered quite efficient due to the balance between coherent quantum evolution and decoherence, a phenomenon coined Environment-Assisted Quantum Transport (ENAQT). Although this effect has been extensively studied, its behavior is typically described in terms of the decoherence’s strength, namely weak, moderate or strong. Here, we study the ENAQT in terms of quantum correlations that go beyond entanglement. Using a subsystem of the Fenna–Matthews–Olson complex, we find that discord-like correlations maximize when the subsystem’s transport efficiency increases, while the entanglement between sites vanishes. Our results suggest that quantum discord is a manifestation of the ENAQT and highlight the importance of beyond-entanglement correlations in photosynthetic energy transport processes.


Sign in / Sign up

Export Citation Format

Share Document