C-phycocyanin and allophycocyanin in two species of blue-green algae

Craig, Ian; Carr, N. G.

doi:10.1042/bj1060361

Cited by 40 publications

(14 citation statements)

References 12 publications

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“…1). The spectroscopic properties of these preparations (phycocyanin A622/A280 = 6.1; allophycocyanin A652/A2so = 3.08, A652/A622 = 1.41, at pH 5.5) compare favorably with those previously reported (8,20). Molecular weights of 224,000 ± 6,000 and 96,000 + 3,000 were obtained for native phycocyanin and allophycocyanin, respectively, by sedimentation equilibrium (21) over a protein concentration range of 0.4-1.0 mg/ml in 0.2 M sodium acetate-i mM ,B-mercaptoethanol at pH 5.5.…”

Section: And Discussionsupporting

confidence: 77%

“…When freshly extracted from the cell under nondenaturing conditions, phycocyanin and phycoerythrin exist predominantly as dissociable aggregates of high molecular weight: reported values range from 220,000 to 340,000 (1-5) for phycoerythrin and from 180,000 to 360,000 for phycocyanin (6)(7)(8)(9). The lowest molecular weight components observed under nondenaturing conditions (assumed to be monomers) are reported to have molecular weights of about 40,000 (10,11) and 23,000 (11) for phycoerythrin, and about 30,000 for phycocyanin (6,9,12).…”

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confidence: 99%

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Subunit Structure of the Phycobiliproteins of Blue-Green Algae

Glazer

Cohen-Bazire

1971

Proc. Natl. Acad. Sci. U.S.A.

101

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The phycobiliproteins of the blue-green algae Synechococcus sp. and Aphanocapsa sp. were characterized with respect to homogeneity, isoelectric point, and subunit composition. Each of the biliproteins consisted of two different noncovalently associated subunits, with molecular weights of about 20,000 and 16,000 for phycocyanin, 17,500 and 15,500 for allophycocyanin, and 22,000 and 20,000 for phycoerythrin. Covalently bound chromophore was associated with each subunit.The phycobiliproteins-phycoerythrin, phycocyanin, and allophycocyanin-function as accessory photosynthetic pigments both in the prokaryotic Cyanophyta and in the eukaryotic Rhodophyta and Cryptophyta (1), a biological distribution that makes them valuable chemical markers for the evolutionist. As a preliminary to more detailed chemical and immunological studies, we have ascertained the subunit structure of all three types of phycobiliproteins isolated from blue-green algae.When freshly extracted from the cell under nondenaturing conditions, phycocyanin and phycoerythrin exist predominantly as dissociable aggregates of high molecular weight: reported values range from 220,000 to 340,000 (1-5) for phycoerythrin and from 180,000 to 360,000 for phycocyanin (6-9). The lowest molecular weight components observed under nondenaturing conditions (assumed to be monomers) are reported to have molecular weights of about 40,000 (10, 11) and 23,000 (11) for phycoerythrin, and about 30,000 for phycocyanin (6,9,12). Kao and Berns (12) have reported the molecular weight of the fundamental subunit of cyanophytan phycocyanins in denaturing solvents to be 30,000. Vaughan (4) has shown that the phycoerythrin of the red alga, Ceramium rubrum, consists of two subunits of molecular weight about 17,000, each carrying chromophore(s). No information is available on the subunit structure of allophycocyanin.In the present study, the phycobiliproteins of two unicellular blue-green algae, with DNAs differing by about 20 mol% in G + C content, have been characterized with respect to homogeneity, isoelectric point, and subunit composition. MATERIALS AND METHODS Preparation of phycobiliproteinsThe source, culture conditions, and properties of the strains used here have been described elsewhere (13). Unless otherwise specified, all operations were performed in sodium acetate buffers that contained 1 mM j3-mercaptoethanol at pH 5.5.Washed Synechococcus sp. (strain 6301) cells were suspended in buffer (1 g wet weight per 10 ml) and broken in a French pressure cell at 20,000 lb/in2 (1330 atm). The suspension was centrifuged at 20,000 X g for 20 min. The supernatant was decanted, and the pellet was washed exhaustively with buffer.The pooled supernatants were brought to 60% saturation with (NH4)2SO4 and left at 4°C for 18 hr. The resulting precipitate from 2 g of cells was dissolved in the minimum volume of buffer, dialyzed against 0.05 M buffer, and applied to a 100 X 2.5 cm column of Sephadex G-200. The fractions with the highest A622/A.a0 (phycocyanin) and A652/An2o (allophyco...

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Section: And Discussionsupporting

confidence: 77%

mentioning

confidence: 99%

Subunit Structure of the Phycobiliproteins of Blue-Green Algae

Glazer

Cohen-Bazire

1971

Proc. Natl. Acad. Sci. U.S.A.

101

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“…(b) Phycocyanin has an absorption maximum at 620 nm, and the decline in extinction at this wavelength was used as a measure of enzymic degradation : L--I% of phycocyanin I,~lcm = 73 [8]). The procedure was improved by centrifugation of the cell-free extract (100 000 g for 90 min) to remove thylakoid fragments containing photosynthetic pigments.…”

Section: Enzymic Assay Of Phycocyaninasementioning

confidence: 99%

A proteolytic enzyme degrading phycocyanin in the cyanobacterium Anabaena cylindrica

Foulds¹

1977

FEMS Microbiology Letters

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“…Nitrogenase activity was measured by the acetylene reduction technique, as described previously (Lambert & Smith, 1980). Phycocyanin (Craig & Carr, 1968) was determined by measuring the A620 of the supernatant obtained during isolation and measurement of cyanophycin by the method of Simon (1973). Urea was determined in the growth medium after the cells had been removed by centrifugation.…”

Section: Methodsmentioning

confidence: 99%

A Role for Nickel in Cyanobacterial Nitrogen Fixation and Growth via Cyanophycin Metabolism

Daday¹,

Mackerras²,

Smith³

1988

Microbiology

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When nickel-depleted cells of Anabaena cylindrica with nitrogenase repressed by growth on ammonia or into late stationary phase) were used to re-initiate nitrogen-fixing growth in fresh nickel-depleted medium a pronounced growth lag was observed. The growth lag was not observed in the presence of NiS04 ( 0 . 6 8~~) .It was associated with delayed heterocyst differentiation, delayed nitrogenase synthesis and inhibition of pigment synthesis. During the lag a pronounced but transient accumulation of cyanophycin was observed, followed by an accumulation of urea in the growth medium. It is proposed that nickel depletion results in a diversion of ammonia from protein synthesis into cyanophycin, thereby delaying the de rwvo synthesis of proteins and enzymes required for the synthesis of active nitrogenase.

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C-phycocyanin and allophycocyanin in two species of blue-green algae

Cited by 40 publications

References 12 publications

Subunit Structure of the Phycobiliproteins of Blue-Green Algae

Subunit Structure of the Phycobiliproteins of Blue-Green Algae

A proteolytic enzyme degrading phycocyanin in the cyanobacterium Anabaena cylindrica

A Role for Nickel in Cyanobacterial Nitrogen Fixation and Growth via Cyanophycin Metabolism

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