Isolation and Characterization of Soluble Boron Complexes in Higher Plants (The Mechanism of Phloem Mobility of Boron)

1.3′:5′-Cyclic AMP was extensively purified from Kalanchoe daigremontiana and Agave americana by neutral alumina and anion- and cation-exchange column chromatography. Inclusion of 3′:5′-cyclic [8-3H]AMP from the point of tissue extraction permitted calculation of yields. The purification procedure removed contaminating material that was shown to interfere with the 3′:5′-cyclic AMP estimation and characterization procedures. 2. The partially purified 3′:5′-cyclic AMP was quantified by means of a radiochemical saturation assay using an ox heart 3′:5′-cyclic AMP-binding protein and by an assay involving activation of a mammalian protein kinase. 3. The plant 3′:5′-cyclic AMP co-migrated with 3′:5′-cyclic [8-3H]AMP on cellulose chromatography, poly(ethyleneimine)-cellulose chromatography and silica-gel t.l.c. developed with several solvent systems. 4. The plant 3′:5′-cyclic AMP was degraded by ox heart 3′:5′-cyclic nucleotide phosphodiesterase at the same rates as authentic 3′:5′-cyclic AMP. 1-Methyl-3-isobutylxanthine (1 mM), a specific inhibitor of the 3′:5′-cyclic nucleotide phosphodieterase, completely inhibited such degradation. 5. The concentrations of 3′:5′-cyclic AMP satisfying the above criteria in Kalanchoe and Agave were 2-6 and 1 pmol/g fresh wt. respectively. Possible bacterial contribution to these analyses was estimated to be less than 0.002pmol/g fresh wt. Evidence for the occurrence of 3′:5′-cyclic AMP in plants is discussed.

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Isolation and Characterization of Photosystem II of Porphyra yezoensis Ueda

Acta Biochimica et Biophysica Sinica ◽

10.1093/abbs/36.11.780 ◽

2004 ◽

Vol 36 (11) ◽

pp. 780-785 ◽

Cited By ~ 5

Author(s):

Zheng-Quan Gao ◽

Guang-Ce Wang ◽

Cheng-Kui Tseng

Keyword(s):

Photosystem Ii ◽

Higher Plants ◽

Porphyra Yezoensis ◽

Sucrose Density Gradient ◽

Thylakoid Membranes ◽

Isolation And Characterization ◽

Sds Page ◽

Cyt C ◽

First Time

Abstract The thylakoid membranes were isolated and purified from gametophyte of Porphyra yezoensis Ueda (P. yezoensis) by sucrose density gradient ultracentrifugation. After P. yezoensis gametophyte thylakoid membranes were solubilized with SDS, the photosystem II (PSII) particles were isolated and purified. The activity of PSII particles was determined with DCIP (2,6-dichloroindophenol) photoreduction reaction. The composition of purified PSII particles was detected by SDS-PAGE. As a result, seven proteins including 55 kD protein, 47 kD protein, 43 kD protein, 33 kD protein, 31 kD protein, 29 kD protein, and 18 kD protein were found. Compared with PSII particles of higher plants and other algae, they were identified as D1/D2 complex, CP47, CP43, 33 kD protein, D1, D2 and cyt c-550 respectively. Besides, other three new proteins of 20 kD, 16 kD and 14 kD respectively were found. Among these extrinsic proteins, the 16 kD and 14 kD proteins had not been reported previously, and the 20 kD protein was found for the first time in multicellular red algae.

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