Phormidium laminosum

ISOLATION AND SOME PROPERTIES OF PHOTOSYNTHETIC MEMBRANE VESICLES ENRICHED IN PHOTOSYSTEM I FROM THE CYANOBACTERIUM PHORMIDIUM LAMINOSUM BY A NON-DETERGENT... 

A relatively simple and quick procedure for the isolation of Photosystem I-enriched particles from the thermophilic cyanobacterium Phormidium laminosum, without the use of detergents for solubilization, is described. The procedure involves sonication of cells, centrifugation and DEAE-cellulose chromatography. The particles had an 02 uptake activity of up to 200 pmol 02. mg chlorophyll h 1 and appeared as vesicles of 200 100 nm diameter when observed under electron microscopy. The analysis of the chlorophyll-protein complexes by polyacrylamide gel electrophoresis showed that these particles are enriched in the complexes associated with Photosystem I and partially depleted in those associated with Photosystem II. The particles did not contain ferredoxin and were active in NADP-photoreduction only in the presence of added ferredox in. They were also able to photoreduce externally added electron mediators using ascorbate as electron donor, the reduced mediators can be coupled to hydrogenase for the production of H2 or for the activation of cyanobacterial phosphoribulokinase using a ferredoxin/thioredoxin system. 

TABLE 1. Purification of PSI-enriched particles from Phormidium laminosum... 

Bowes, J.M., Horton, P. and Bendall, D.S. 1983a. Characterization of photosystem II electron acceptors in Phormidium laminosum. Arch. Biochem. Biophys., 225, 353-359. 

Bowes, J.M., Stewart, A.C. and Bendall, D.S. 1983b. Purification of photosystem II from Phormidium laminosum using the detergent dodecyl-p-D-maltoside. Biochim. Biophys. Acta, 725.210-219. 

Serra, J.L., Llama, M.J., Rao, K.K. and Hall, D.O. 1986. B-5 Hydrogen photoproduction using photosystem I-enriched particles from Phormidium laminosum. Book of Abstracts 6th International Conference on Photochemical Conversion and Storage of Solar Energy, Lab. Biophysique, INSERM, Paris. 

Carrell CJ, Schlarb BG, Bendall DS, Howe CJ, Cramer WA, Smith JL. Structure of the soluble domain of c)4ochrome f from the cyanobacterium. Phormidium laminosum. Biochemistry 1999 38 9590-9599. 

R Cammack MD Ryan and AC Stewart(1979) The EPR spectrum of Iron-sulfur centre B in photosystem I in Phormidium laminosum. FEBS Lett 108 422-426... 

The electron acceptor complex of photosystem 2 from Phormidium laminosum. 

Redox titrations using EPR and laser flash absorption spectroscopy of the electron acceptor complex in Phormidium laminosum photosystem 2 particles which apparently lack (4) are reported as these preparations offer a model system to determine the identity of the components of the electron acceptor complex. The g=1.6 EPR signal previously described in Synechocystis has also been observed in P. laminosum (5). The redox properties and effect of inhibitors and pH on the g=1.6 signal suggest its appearance reflects the redox behaviour of Qj. ... 

THE STATE OF THE IRON IN THE OXYGEN-EVOLVING CORE COMPLEX (OECC) OF PHORMIDIUM LAMINOSUM BY MOSSBAUER SPECTROSCOPY. 

Photosystem ll-enriched membrane fragments were isolated from spinach chloroplasts (2,4) and Phormidium laminosum. Steady state O2 evolution rates at the time of preparation were 500 to 1000 pmol per mg Chl.per h, measured in an oxygen electrode in the presence of a benzoquinone derivate as electron acceptor. Electrodes coated with Ti02 were made as described in (5). The electrode surface was sensitized with the dye cis-diaqua Ru(ll) 2,2 -bipyridyi-... 

In the case of the thermophilic cyanobacterium Synecho-coccus sp. and Phormidium laminosum, an oligomeric structure has been detected (6,7). Both bacteria gave evidence for a monomeric and trimeric organization of the isolated RC I complexes (7,20,18). In vivo, however, for both bacteria a monomeric structure for PS I was reported (2,18), questioning a PS trimer in vivo. The mass of these monomeric complexes in vivo also is a matter of debate, ranging from 150 kDa to 400 kDa (6,2), as well as the amount of antenna chlorophyll per reaction center Chl-aj, ranging from 50 up to 130 (3,2). In this contribution 3 different complexes of PS I have been isolated. Similar polypeptide composition and antenna chlorophyll per Chl-aj, etc. give evidence that the complexes represent monomers, dimers and trimers of the same miminal RC I unit. The s ize, shape, mass and activity of this unit have been estimated. 

The Electron Acceptor Complex of Photosystem 2 from Phormidium laminosum 523... 

A. Blanco, B. Sanz, M.J. Llama and J.L. Serrei, Biosorption of heavy metals to immobilized Phormidium laminosum biomass, /. BiotechnoL, 69, 227-240 (1999). 

PROPERTIES OF PURIFIED OXYGEN-EVOLVING PHOTOSYSTEM II PARTICLES FROM THE BLUE-GREEN ALGA, PHORMIDIUM LAMINOSUM... 

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