1
|
Bryant DA, Gisriel CJ. The structural basis for light harvesting in organisms producing phycobiliproteins. THE PLANT CELL 2024; 36:4036-4064. [PMID: 38652697 PMCID: PMC11449063 DOI: 10.1093/plcell/koae126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 03/13/2024] [Accepted: 03/20/2024] [Indexed: 04/25/2024]
Abstract
Cyanobacteria, red algae, and cryptophytes produce 2 classes of proteins for light harvesting: water-soluble phycobiliproteins (PBP) and membrane-intrinsic proteins that bind chlorophylls (Chls) and carotenoids. In cyanobacteria, red algae, and glaucophytes, phycobilisomes (PBS) are complexes of brightly colored PBP and linker (assembly) proteins. To date, 6 structural classes of PBS have been described: hemiellipsoidal, block-shaped, hemidiscoidal, bundle-shaped, paddle-shaped, and far-red-light bicylindrical. Two additional antenna complexes containing single types of PBP have also been described. Since 2017, structures have been reported for examples of all of these complexes except bundle-shaped PBS by cryogenic electron microscopy. PBS range in size from about 4.6 to 18 mDa and can include ∼900 polypeptides and bind >2000 chromophores. Cyanobacteria additionally produce membrane-associated proteins of the PsbC/CP43 superfamily of Chl a/b/d-binding proteins, including the iron-stress protein IsiA and other paralogous Chl-binding proteins (CBP) that can form antenna complexes with Photosystem I (PSI) and/or Photosystem II (PSII). Red and cryptophyte algae also produce CBP associated with PSI but which belong to the Chl a/b-binding protein superfamily and which are unrelated to the CBP of cyanobacteria. This review describes recent progress in structure determination for PBS and the Chl proteins of cyanobacteria, red algae, and cryptophytan algae.
Collapse
Affiliation(s)
- Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | | |
Collapse
|
2
|
Parys E, Krupnik T, Kułak I, Kania K, Romanowska E. Photosynthesis of the Cyanidioschyzon merolae cells in blue, red, and white light. PHOTOSYNTHESIS RESEARCH 2021; 147:61-73. [PMID: 33231791 PMCID: PMC7728651 DOI: 10.1007/s11120-020-00796-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/06/2020] [Indexed: 05/19/2023]
Abstract
Photosynthesis and respiration rates, pigment contents, CO2 compensation point, and carbonic anhydrase activity in Cyanidioschizon merolae cultivated in blue, red, and white light were measured. At the same light quality as during the growth, the photosynthesis of cells in blue light was significantly lowered, while under red light only slightly decreased as compared with white control. In white light, the quality of light during growth had no effect on the rate of photosynthesis at low O2 and high CO2 concentration, whereas their atmospheric level caused only slight decrease. Blue light reduced markedly photosynthesis rate of cells grown in white and red light, whereas the effect of red light was not so great. Only cells grown in the blue light showed increased respiration rate following the period of both the darkness and illumination. Cells grown in red light had the greatest amount of chlorophyll a, zeaxanthin, and β-carotene, while those in blue light had more phycocyanin. The dependence on O2 concentration of the CO2 compensation point and the rate of photosynthesis indicate that this alga possessed photorespiration. Differences in the rate of photosynthesis at different light qualities are discussed in relation to the content of pigments and transferred light energy together with the possible influence of related processes. Our data showed that blue and red light regulate photosynthesis in C. merolae for adjusting its metabolism to unfavorable for photosynthesis light conditions.
Collapse
Affiliation(s)
- Eugeniusz Parys
- Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Tomasz Krupnik
- Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Ilona Kułak
- Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Kinga Kania
- Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Elżbieta Romanowska
- Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland.
| |
Collapse
|
3
|
Schrantz K, Wyss PP, Ihssen J, Toth R, Bora DK, Vitol EA, Rozhkova EA, Pieles U, Thöny-Meyer L, Braun A. Hematite photoanode co-functionalized with self-assembling melanin and C-phycocyanin for solar water splitting at neutral pH. Catal Today 2017. [DOI: 10.1016/j.cattod.2016.10.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
4
|
Su HN, Xie BB, Zhang XY, Zhou BC, Zhang YZ. The supramolecular architecture, function, and regulation of thylakoid membranes in red algae: an overview. PHOTOSYNTHESIS RESEARCH 2010; 106:73-87. [PMID: 20521115 DOI: 10.1007/s11120-010-9560-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Accepted: 05/10/2010] [Indexed: 05/29/2023]
Abstract
Red algae are a group of eukaryotic photosynthetic organisms. Phycobilisomes (PBSs), which are composed of various types of phycobiliproteins and linker polypeptides, are the main light-harvesting antennae in red algae, as in cyanobacteria. Two morphological types of PBSs, hemispherical- and hemidiscoidal-shaped, are found in different red algae species. PBSs harvest solar energy and efficiently transfer it to photosystem II (PS II) and finally to photosystem I (PS I). The PS I of red algae uses light-harvesting complex of PS I (LHC I) as a light-harvesting antennae, which is phylogenetically related to the LHC I found in higher plants. PBSs, PS II, and PS I are all distributed throughout the entire thylakoid membrane, a pattern that is different from the one found in higher plants. Photosynthesis processes, especially those of the light reactions, are carried out by the supramolecular complexes located in/on the thylakoid membranes. Here, the supramolecular architecture, function and regulation of thylakoid membranes in red algal are reviewed.
Collapse
Affiliation(s)
- Hai-Nan Su
- The State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, People's Republic of China
| | | | | | | | | |
Collapse
|
5
|
Lemaux PG, Grossman A. Isolation and characterization of a gene for a major light-harvesting polypeptide from Cyanophora paradoxa. Proc Natl Acad Sci U S A 2010; 81:4100-4. [PMID: 16593484 PMCID: PMC345376 DOI: 10.1073/pnas.81.13.4100] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Antibodies raised against mixtures of phycobilisome polypeptides from the eukaryotic alga Cyanidium caldarium were used in an immunological screen to detect expression of phycobiliprotein genes in an Escherichia coli library containing segments of plastid (chloroplast, cyanelle) DNA from another eukaryotic alga, Cyanophora paradoxa. The four candidate clones obtained were mapped by restriction analysis and found to be overlapping. The clone with the smallest insert (1.4 kilobases) was partially sequenced and a coding region similar to the carboxyl terminus of the phycobiliprotein subunit beta-phycocyanin was found. The coding region for the beta-phycocyanin gene in C. paradoxa has been mapped to the small single copy region on the cyanelle genome, and its orientation has been determined. A short probe unique to a conserved chromophore binding site shared by at least two phycobiliprotein subunits has now been generated from the carboxyl terminus of the beta-phycocyanin gene. This probe may be useful in identifying specific phycobiliprotein subunit genes, beta-phycocyanin, beta-phycoerythrocyanin, and possibly beta-phycoerythrin, in other eukaryotic algae and in prokaryotic cyanobacteria.
Collapse
Affiliation(s)
- P G Lemaux
- Department of Plant Biology, Carnegie Institution of Washington, 290 Panama Street, Stanford, CA 94305
| | | |
Collapse
|
6
|
Abstract
A kinetic model for the energy transfer in phycobilisome (PBS) rods of Synechococcus 6301 is presented, based on a set of experimental parameters from picosecond studies. It is shown that the enormous complexity of the kinetic system formed by 400-500 chromophores can be greatly simplified by using symmetry arguments. According to the model the transfer along the phycocyanin rods has to be taken into account in both directions, i.e., back and forth along the rods. The corresponding forward rate constants for single step energy transfer between trimeric disks are predicted to be 100-300 ns(-1). The model that best fits the experimental data is an asymmetric random walk along the rods with overall exciton kinetics that is essentially trap-limited. The transfer process from the sensitizing to the fluorescing C-PC phycocyanin chromophores (tau approximately 10 ps) is localized in the hexamers. The transfer from the innermost phycocyanin trimer to the core is calculated to be in the range 36-44 ns(-1). These parameters lead to calculated overall rod-core transfer times of 102 and 124 ps for rods containing three and four hexamers, respectively. The model calculations confirm the previously suggested hypothesis that the energy transfer from the rods to the core is essentially described by one dominant exponential function. Extension of the model to heterogeneous PBS rods, i.e., PBS containing also phycoerythrin, is straightforward.
Collapse
|
7
|
Desquilbet TE, Duval JC, Robert B, Houmard J, Thomas JC. In the Unicellular Red Alga Rhodella violacea Iron Deficiency Induces an Accumulation of Uncoupled LHC. ACTA ACUST UNITED AC 2003; 44:1141-51. [PMID: 14634150 DOI: 10.1093/pcp/pcg139] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Iron plays a key role in the synthesis and functioning of the photosynthetic apparatus. Conditions of partial iron deficiency that lead to a relatively stable phenotype were established and the effects of starvation studied in the unicellular red alga, Rhodella violacea. Synthesis of the photosynthetic pigments were found to decrease, with phycobiliproteins being affected to a lesser extent than chlorophyll a. Biophysical, biochemical and immunological approaches were used to show that the PSI content is highly diminished and the PSII/PSI stoichiometry increased by a factor of 5 compared to standard conditions. Meanwhile light-harvesting complex (LHC) was still assembled in the thylakoid membranes at unchanged levels. The use of translation inhibitors for either nuclear- or plastid-encoded polypeptides revealed that uncoupled LHC may be responsible for the high wavelength-fluorescence contribution observed around 700-710 nm. There is no evidence for the synthesis of new chlorophyll-protein complexes.
Collapse
Affiliation(s)
- Thibaut E Desquilbet
- Organismes Photosynthétiques et Environnement, CNRS-ENS FRE2433, Département de Biologie de l'Ecole Normale Supérieure, 46 rue d'Ulm, F-75230 Paris Cedex 05, France
| | | | | | | | | |
Collapse
|
8
|
Doan JM, Schoefs B, Ruban AV, Etienne AL. Changes in the LHCI aggregation state during iron repletion in the unicellular red alga Rhodella violacea. FEBS Lett 2003; 533:59-62. [PMID: 12505159 DOI: 10.1016/s0014-5793(02)03748-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Red algae are well suited to study the effects of iron deficiency on light-harvesting complex for photosystem I (LHCI), since they are totally devoid of light-harvesting complex for photosystem II (LHCII). Iron starvation results in a reduction of the pigment content, an increase of the fluorescence yield and a new emission band at 705 nm in the 77 K fluorescence emission spectra. These changes reflect the accumulation of uncoupled, aggregated LHCI in iron-depleted cells. Reconnection of LHCI to de novo synthesized reaction center I (RCI) is the first event, which takes place after iron addition. The changes in the aggregation state of LHCI are likely to occur also in brown and green algae.
Collapse
Affiliation(s)
- Jean Michel Doan
- Organismes Photosynthétiques et Environnement, UMR 8543 CNRS, Département de Biologie, ENS 46 rue d'Ulm, 75230 cedex 05, Paris, France
| | | | | | | |
Collapse
|
9
|
Gillbro T, Sandström Å, Sundström V, Holzwarth AR. Polarized absorption picosecond kinetics as a probe of energy transfer in phycobilisomes of Synechococcus
6301. FEBS Lett 2001. [DOI: 10.1016/0014-5793(83)81050-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
10
|
Ritz M, Thomas JC, Spilar A, Etienne AL. Kinetics of photoacclimation in response to a shift to high light of the red alga Rhodella violacea adapted to low irradiance. PLANT PHYSIOLOGY 2000; 123:1415-26. [PMID: 10938358 PMCID: PMC59098 DOI: 10.1104/pp.123.4.1415] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/1999] [Accepted: 04/03/2000] [Indexed: 05/21/2023]
Abstract
The unicellular rhodophyte Rhodella violacea can adapt to a wide range of irradiances. To create a light stress, cells acclimated to low light were transferred to higher irradiance and the kinetics of various changes produced by the light shift were analyzed. The proton gradient generated by excess light led to a non-photochemical quenching of the chlorophyll fluorescence and some photoinhibition of photosystem II centers was also produced by the light stress. After the shift to higher irradiance, the mRNA levels of three chloroplast genes that encode phycoerythrin and phycocyanin apoproteins and heme oxygenase (the first enzyme specific to the bilin synthesis) were negatively regulated. A change in the amount of thylakoids and in the total pigment content of the cells occurred during light acclimation after a light stress. The change in the size of the phycobilisome was limited to dissapearance of the terminal phycoerythrin hexamers in some of the rods. The ability of R. violacea to photoacclimate depends both on large changes in thylakoid number and pigment content and on smaller changes in the antenna size of photosystem II.
Collapse
Affiliation(s)
- M Ritz
- Laboratoire Dynamique des Membranes Végétales-Complexes Proteines-Pigments, Unité de Recherche Associée 1810 Centre National de la Recherche Scientifique, Ecole Normale Supérieure, 46 rue d'Ulm, 75230 Paris cedex 05, France
| | | | | | | |
Collapse
|
11
|
Thomas JC, Passaquet C. Characterization of a phycoerythrin without alpha-subunits from a unicellular red alga. J Biol Chem 1999; 274:2472-82. [PMID: 9891018 DOI: 10.1074/jbc.274.4.2472] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We describe here the spectral and biochemical properties of a novel biliprotein belonging to the phycoerythrin family, purified from the phycobilisome of a unicellular red alga, Rhodella reticulata strain R6. This biliprotein is assembled from a unique beta-type subunit, chloroplast-encoded, whose hexameric or dodecameric aggregates are stabilized by unusually large linkers (87 and 60 kDa) encoded by the nuclear genome. Although each beta-type subunit bears two phycoerythrobilins and one phycocyanobilin per chain, the linker polypeptides are non-chromophorylated. The apoprotein of the beta-subunit of the R. reticulata R6 phycoerythrin is specified by a monocistronic rpeB chloroplast gene that is split into three exons. We discuss the relationships between R6 beta-phycoerythrin and the previously published polypeptide sequences, the structural consequences due to the absence of an alpha-subunit, and its evolutionary implications.
Collapse
Affiliation(s)
- J C Thomas
- Laboratoire de Photorégulation et Dynamique des Membranes Végétales, CNRS, Unité de Recherche Associée 1810, GDR 1002, Ecole Normale Supérieure, 46 rue d'Ulm, 75 230 Paris Cedex 05, France.
| | | |
Collapse
|
12
|
Mihova S, Georgiev D, Minkova K, Tchernov A. Phycobiliproteins in Rhodella reticulata and photoregulatory effects on their content. J Biotechnol 1996. [DOI: 10.1016/0168-1656(96)01515-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
13
|
Culture of an autoflocculent microalga in a vertical tubular photobioreactor for phycoerythrin production. ACTA ACUST UNITED AC 1995. [DOI: 10.1007/bf00157076] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
14
|
Reuter W, Nickel C, Wehrmeyer W. Isolation of allophycocyanin B from Rhodella violacea results in a model of the core from hemidiscoidal phycobilisomes of rhodophyceae. FEBS Lett 1990; 273:155-8. [PMID: 2226847 DOI: 10.1016/0014-5793(90)81073-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Two 'trimeric' allophycocyanin complexes could be isolated from the hemidiscoidal phycobilisomes of Rhodella violacea. AP = (alpha *AP alpha 2AP beta 2AP beta *AP) and APB = (alpha *AP alpha AP alpha APB beta 2AP beta *AP). Lc13.5APB. The isolation was performed by combined methods of gradient centrifugation, hydroxylapatite chromatography and 'native' polyacrylamide gel electrophoresis. AP showed the well-known spectral characteristics of allophycocyanin without linker polypeptide. APB is characterized by its long wavelength absorbing shoulder (675 nm) and fluorescence emission (682 nm), respectively. The existence of two low molecular linker polypeptides Lc12.5 and Lc13.5APB in the phycobilisomes of Rhodella violacea, their stoichiometric calculations and the localization of Lc13.5APB in allophycocyanin B facilitated the construction of a model of the phycobilisome core.
Collapse
Affiliation(s)
- W Reuter
- Fachbereich Biologie der Universität, Marburg, FRG
| | | | | |
Collapse
|
15
|
van Grondelle R. Excitation energy transfer, trapping and annihilation in photosynthetic systems. ACTA ACUST UNITED AC 1985. [DOI: 10.1016/0304-4173(85)90017-5] [Citation(s) in RCA: 228] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
16
|
Picosecond study of energy-transfer kinetics in phycobilisomes of Synechococcus 6301 and the mutant AN 112. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1985. [DOI: 10.1016/0005-2728(85)90027-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
17
|
|
18
|
Wendler J, Holzwarth A, Wehrmeyer W. Picosecond time-resolved energy transfer in phycobilisomes isolated from the red alga Porphyridium cruentum. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1984. [DOI: 10.1016/0005-2728(84)90157-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
19
|
Holzwarth AR, Wendler J, Wehrmeyer W. PICOSECOND TIME RESOLVED ENERGY TRANSFER IN ISOLATED PHYCOBILISOMES FROM RHODELLA VIOLACEA (RHODOPHYCEAE). Photochem Photobiol 1982. [DOI: 10.1111/j.1751-1097.1982.tb04405.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
20
|
Nies M, Wehrmeyer W. Biliprotein assembly in the hemidiscoidal phycobilisomes of the thermophilic cyanobacterium Mastigocladus laminosus Cohn. Characterization of dissociation products with special reference to the peripheral phycoerythrocyanin-phycocyanin complexes. Arch Microbiol 1981. [DOI: 10.1007/bf00406466] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
21
|
Nies M, Wehrmeyer W. Isolation and biliprotein characterization of phycobilisomes from the thermophilic cyanobacterium Mastigocladus laminosus Cohn. PLANTA 1980; 150:330-337. [PMID: 24306806 DOI: 10.1007/bf00384663] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/1980] [Accepted: 09/03/1980] [Indexed: 06/02/2023]
Abstract
A method for the effective isolation of functionally intact phycobilisomes from the thermophilic cyanobacterium M. laminosus is presented, using an unconventional high buffer molarity for stabilizing the aggregates and introducing a DNAse treatment of the disrupted cells to obtain sharp banding of the phycobilisomes in the linear sucrose density gradients.The structural integrity of the isolated phycobilisomes is demonstrated by a fluorescence emission maximum at 673 nm of aggregated allophycocyanin and by electron microscopy.Besides C-phycocyanin and allophycocyanin, phycoerythrocyanin is a constituent pigment of the phycobilisomes. These pigments indicated in the absorption spectrum of phycobilisomes with a maximum at 610 nm and two shoulders at 650 and 580 nm, respectively, were characterized by spectral data and isoelectric points.
Collapse
Affiliation(s)
- M Nies
- Botanik, Fachbereich Biologie der Philipps-Universität, Lahnberge, D-3550, Marburg, Federal Republic of Germany
| | | |
Collapse
|
22
|
Troxler R, Greenwald L, Zilinskas B. Allophycocyanin from Nostoc sp. phycobilisomes. Properties and amino acid sequence at the NH2 terminus of the alpha and beta subunits of allophycocyanins I, II, and III. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)70573-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
23
|
Gantt E. Structure and Function of Phycobilisomes: Light Harvesting Pigment Complexes in Red and Blue-Green Algae. INTERNATIONAL REVIEW OF CYTOLOGY 1980. [DOI: 10.1016/s0074-7696(08)61971-3] [Citation(s) in RCA: 168] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
|
24
|
|
25
|
Koller KP, Wehrmeyer W, Mörschel E. Biliprotein assemble in the disc-shaped phycobilisomes of Rhodella violacea. On the molecular composition of energy-transfering complexes (tripartite units) forming the periphery of the phycobilisome. EUROPEAN JOURNAL OF BIOCHEMISTRY 1978; 91:57-63. [PMID: 720347 DOI: 10.1111/j.1432-1033.1978.tb20936.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Heterogeneous complexes with a molecular weight of about 790000 containing B-phycoerythrin (Bangiales phycoerythrin) and C-phycocyanin (Cyanophyceae phycocyanin) in a molar pigment ratio of 2:1 were isolated from purified, dissociated phycobilisomes. Electron microscopical investigations revealed structures of three discs aggregated face to face with an apparent distance of 1.5 nm between each disc. Two discs may represent phycoerythrin and one phycocyanin. The complexes are structurally identical with tripartite units of the phycobilisome periphery. Fluorescence data confirmed the integrity of isolated tripartite units. Excitation at 546 nm gives a fluorescence maximum at 644 nm, indicating intermolecular transfer of excitation energy from phycoerythrin to phycocyanin. Comparative subunit analyses and spectral data suggested that no allophycocyanin is present. Cross-linking experiments gave evidence for a polar arrangement of phycocyanin within the complex. This pigment itself is an aggregate of two smaller molecules each having a molecular weight of about 140000. Tripartite units contain all the phycoerythrin and phycocyanin of the phycobilisome. On this basis, a phycobilisome model is proposed which combines the aspects of biliprotein distribution, energy transfer and fine structure.
Collapse
|
26
|
Yamanaka G, Glazer A, Williams R. Cyanobacterial phycobilisomes. Characterization of the phycobilisomes of Synechococcus sp. 6301. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34397-1] [Citation(s) in RCA: 109] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
|
27
|
Searle GF, Barber J, Porter G, Tredwell CJ. Picosecond time-resolved energy transfer in Porphyridium cruentum. Part II. In the isolated light harvesting complex (phycobilisomes). BIOCHIMICA ET BIOPHYSICA ACTA 1978; 501:246-56. [PMID: 620015 DOI: 10.1016/0005-2728(78)90030-0] [Citation(s) in RCA: 108] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The transfer of excitation energy between phycobiliproteins in isolated phycobilisomes has been observed on a picosecond time scale. The photon density of the excitation pulse has been carefully varied so as to control the level of exciton interactions induced in the pigment bed. The 530 nm light pulse is absorbed predominantly by B-phycoerythrin, and the fluorescence of this component rises within the pulse duration and shows a mean 1/e decay time of 70 ps. The main emission band, centred at 672 nm, is due to allophycocyanin and is prominent because of the absence of energy transfer to chlorophyll. Energy transfer to this pigment from B-phycoerythrin via R-phycocyanin produces a risetime of 120 ps to the fluorescence maximum. The lifetime of the allophycocyanin fluorescence is found to be about 4 ns using excitation pulses of low photon densities (10(13) photons.cm-2), but decreases to about 2 ns at higher photon densities. The relative quantum yield of the allophycocyanin fluorescence decreases almost 10 fold over the range of laser pulse intensities, 10(13)--10(16) photons-cm-2. Fluorescence quenching by exciton-exciton annihilation is only observed in allophycocyanin and could be a consequence of the long lifetime of the single exciton in this pigment.
Collapse
|