As a model of photosynthetic unit (PSU), self-assembled aggregates of pigment-protein complexes from photosynthetic bacteria were prepared in a lipid bilayer by reconstitution of the light-harvesting 2 (LH2) complex and light-harvesting 1-reaction center (LH1-RC) complex through detergent removal of their micelles in the presence of lipids. By performing polarization-controlled fluorescence and fluorescence-excitation spectroscopy on single aggregates at a temperature of 5 K, the composition of individual aggregates was determined and excitation energy transfer (EET) between constituent complexes was observed. LH2 and LH1-RC from a bacterium, Rhodobacter (Rb.) sphaeroides, were found to form a trimeric aggregate in which EET takes place from one LH2 to two LH1-RCs. In contrast, a heterodimer of LH2 and LH1-RC in which EET works was found to assemble from a combination of complexes of different bacterial species, that is, LH2 from Rb. sphaeroides and LH1-RC from Rhodopseudomonas (Rps.) palustris.

Download full-text PDF

Source
http://dx.doi.org/10.1039/c1cp20172gDOI Listing

Publication Analysis

Top Keywords

photosynthetic unit
8
lipid bilayer
8
lh2 lh1-rc
8
lh2
5
reconstitution bacterial
4
bacterial photosynthetic
4
unit lipid
4
bilayer studied
4
studied single-molecule
4
single-molecule spectroscopy
4

Similar Publications

Stomata control plant water loss and photosynthetic carbon gain. Developing more generalized and accurate stomatal models is essential for earth system models and predicting responses under novel environmental conditions associated with global change. Plant optimality theories offer one promising approach, but most such theories assume that stomatal conductance maximizes photosynthetic net carbon assimilation subject to some cost or constraint of water.

View Article and Find Full Text PDF

Biochemical evidence for the diversity of LHCI proteins in PSI-LHCI from the red alga Galdieria sulphuraria NIES-3638.

Photosynth Res

January 2025

Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.

Red algae are photosynthetic eukaryotes whose light-harvesting complexes (LHCs) associate with photosystem I (PSI). In this study, we examined characteristics of PSI-LHCI, PSI, and LHCI isolated from the red alga Galdieria sulphuraria NIES-3638. The PSI-LHCI supercomplexes were purified using anion-exchange chromatography followed by hydrophobic-interaction chromatography, and finally by trehalose density gradient centrifugation.

View Article and Find Full Text PDF

Freshwater depletion becomes a significant challenge as the population grows and food demand rises. We evaluated the responses of lettuce cultivars () under saline stress in photosynthetic responses, production, and ion homeostasis. We used a randomized block design in a 3 × 5 factorial scheme with five replications-the first factor: three cultivars of curly lettuce: SVR 2005, Simpson, and Grand Rapids.

View Article and Find Full Text PDF

The selection of an appropriate and targeted crop protection technology for winter oilseed rape is crucial for the economic production of this crop. Insecticides belonging to the group of diamides and butenolides are available as seed treatments for winter oilseed rape and serve as effective tools for chemical crop protection. The objective of this study was to determine the multi-directional applicability of the active ingredients cyantraniliprole and flupyradifurone.

View Article and Find Full Text PDF

Evaluating the tolerance of harmful algal bloom communities to copper.

Environ Pollut

January 2025

School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL. Electronic address:

Harmful algal blooms (HABs) cause severe economic and environmental impacts, including hypoxic events and the production of toxins and off-flavor compounds. Chemical treatments, such as copper sulfate pentahydrate (CuSO·5HO), are often used to mitigate the damaging effects of algal blooms. However, treatment effects are usually short-lived leading to waterbodies requiring repeated CuSO·5HO applications to control persistent algal blooms, particularly in highly eutrophic systems, such as aquaculture ponds or small agricultural impoundments.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!