Energy distribution in the photochemical apparatus of Porphyridium cruentum: Picosecond fluorescence spectroscopy of cells in state 1 and state 2 at 77 K

Bruce, Doug; Hanzlik, Cheryl A.; Hancock, Lucia E.; Biggins, John; Knox, Robert

doi:10.1007/bf00118292

Cited by 15 publications

(2 citation statements)

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“…Bruce et al (1985) have come to a similar conclusion on the basis of time-resolved picosecond fluorescence measurements on red and blue-green algae. (Also see Bruce et al, 1986). Bruce and Biggins (1985) reported differences in the low temperature linear dichroism spectra of Anacystis cells chemically fixed in State 1 or State 2 which they suggested might reflect changes in orientation of the allo-phycocyanin core of the phycobilisomes.…”

Section: Excitation Energy Distribution In Red and Blue-green Algaementioning

confidence: 99%

State 1/State 2 changes in higher plants and algae

1987

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Current ideas regarding the molecular basis of State 1/State 2 transitions in higher plants and green algae are mainly centered around the view that excitation energy distribution is controlled by phosphorylation of the light-harvesting complex of photosystem II (LHC-II). The evidence supporting this view is examined and the relationship of the transitions occurring in these systems to the corresponding transitions seen in red and blue-green algae is explored.

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Section: Excitation Energy Distribution In Red and Blue-green Algaementioning

confidence: 99%

State 1/State 2 changes in higher plants and algae

1987

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“…In this study, we used time-resolved fluorescence measurements at 77 K to study state transitions in wild-type (WT) Synechococcus elongatus 7942 cells. Timeresolved fluorescence measurements have been used before to study light harvesting and its regulation in cyanobacteria (Bruce et al 1985(Bruce et al , 1986Krumova et al 2010;Tian et al 2011Tian et al , 2013Chukhutsina et al 2015a, b;van Stokkum et al 2018). This study attempts (1) to reveal the differences in EET in state I and II and to verify/falsify existing models for state transitions; and (2) to assess whether state I-light II transitions and state II-light II transitions involve the same processes (light I/II is the light with spectral composition that preferentially excites Photosystem I/II).…”

Section: Target Analysismentioning

confidence: 99%

Studying photosynthetic antenna complexes in vivo and in vitro using time-resolved fluorescence spectroscopy

Choubeh

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Chapter 1 Introduction 7 Chapter 2 Picosecond excitation energy transfer of allophycocyanin studied in solution and in crystals 33 Chapter 3 State transitions in the cyanobacterium Synechococcus elongatus 7942 involve reversible quenching of the photosystem II core 57 Chapter 4 Light harvesting dynamics in desert crust cyanobacteria: Changes in aggregation state as a mechanism for modulating energy transfer 93 Chapter 5 Efficiency of excitation-energy trapping in the reaction center of the low-light adapted green photosynthetic bacterium Chlorobaculum tepidum 129 Chapter 6 General discussion 163 Chapter 7 Summary 175 Acknowledgements 179 Photosynthesis, cyanobacteria, and state transitions Photosynthetic organisms convert light energy into chemical energy to sustain their metabolism, but which can also be used by other living organisms. Photosynthetic reactions are divided into light-dependent and light-independent reactions (Blankenship 2008a). Plants and cyanobacteria produce Adenosine Triphosphate (ATP) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) during the light-dependent reactions. In the light-independent reactions, ATP and NADPH are used to fix carbon dioxide into carbohydrates. The light-dependent reactions start with the absorption of light by the photosynthetic antennas. Cyanobacteria use phycobilisomes (PBSs) and photosystems I and II (PSI and PSII) to absorb light (Figure 1). PBSs are the main light-harvesting antennas in cyanobacteria which mainly absorb green-orange light. They are composed of rodlike proteins and core proteins. (MacColl 2004; Mirkovic et al. 2016). The rods are built of C-phycocyanins (CPCs) and in various organisms they also have phycoerythrins (PEs). The rods are attached to allophycocyanins (APCs), which contain APC trimers and three other protein-pigments, namely LCM, β 16 , and α B. The excitation energy absorbed by PEs and PCs travels along the rods and reaches APCs, which are attached to the rods by linker proteins, and from there it is delivered in cyan. The dotted line separates one monomer. The codes in the protein data bank are 1jbo (CPC) and 4rmp (APC). PSII is another multi-subunit complex present in cyanobacteria, which is generally believed to form dimers in vivo (Nelson and Ben-Shem 2004; Nickelsen and Rengstl 2013; Zlenko et al. 2017) (Figure 3). The PSII reaction center complex largely consists of two proteins, D1 and D2 and binds six chlorophylls a, two pheophytins a a, two pheophytin and two quinone molecules as described as follows. PD1 and PD2, which are Chls a, are shown in red and blue and next to them are two other Chls a in green, which are called ChlD1 and ChlD2. The pheophytin molecules (PheD1 and PheD2) are represented in black and the quinones in purple. The bottom of the figure shows two different pathways that result in the same chargeseparated state. Only one branch is active in charge separation. The star shows the excited state and the rectangles show the charge-separated states. it takes up one proton from the stroma (two in t...

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Streak Cameras for Time-Domain Fluorescence

Nordlund

Topics in Fluorescence Spectroscopy

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Energy distribution in the photochemical apparatus of Porphyridium cruentum: Picosecond fluorescence spectroscopy of cells in state 1 and state 2 at 77 K

Cited by 15 publications

References 18 publications

State 1/State 2 changes in higher plants and algae

State 1/State 2 changes in higher plants and algae

Studying photosynthetic antenna complexes in vivo and in vitro using time-resolved fluorescence spectroscopy

Streak Cameras for Time-Domain Fluorescence

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