Reduction of ferric chelates by leaf plasma membrane preparations from Fe-deficient and Fe-sufficient sugar beet

1999 ◽  
Vol 26 (6) ◽  
pp. 601 ◽  
Author(s):  
Elena B. González-Vallejo ◽  
Anunciación Abadía ◽  
Jose Antonio González-Reyes ◽  
Javier Abadía ◽  
Ana Flor López-Millán ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Citric Acid ◽  
Sugar Beet ◽  
Plasma Membranes ◽  
Ferric Iron ◽  
Reductase Activity ◽  
Tetraacetic Acid ◽  
Ferric Chelate Reductase ◽  
Ferric Chelate Reductase Activity ◽  
Optimal Ph

The ferric chelate reductase activities of leaf plasma membranes isolated from the leaves of Fe-deficient and Fe-sufficient sugar beet have been characterized. Substrates used were the complexes of ferric iron with ethylene diamine tetraacetic acid, citric acid and malic acid. Iron deficiency was associated with 1.5- to 2-fold increases in leaf plasma membrane ferric chelate reductase activity when rates were calculated on a protein basis. The natural complexes of ferric iron with citrate and especially with malate were good substrates for the ferric chelate reductase enzyme present in leaf plasma membrane preparations. The apparent affinities were higher for the ferric malate complex. The optimal pH for the activity of the ferric chelate reductase in sugar beet leaf plasma membranes was in the range 6.5–7.0. The ferric chelate reductase activity decreased by approximately 30% when the assay pH was decreased to 5.8 or increased to 7.5. Therefore, our data provide evidence against the hypothesis that changes in apoplastic pH could decrease markedly the activity of the ferric chelate reductase enzyme in plasma membrane preparations from the leaves of Fe-deficient plants.

scholarly journals CAN COPPER AND ZINC IN DIFFERENT CHEMICAL FORMS IMPROVE IRON DEFICIENT IN PHASEOLUS PLANT

2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Salama & El Fouly
Keyword(s):  
Superoxide Dismutase ◽  
Plasma Membrane ◽  
Iron Deficiency ◽  
Reductase Activity ◽  
Chemical Forms ◽  
Ferric Chelate Reductase ◽  
Iron Deficient ◽  
Ferric Chelate Reductase Activity ◽  
Root Plasma Membrane ◽  
Ionic Forms

This study was aimed to compare between the effects of different chemical forms of Zn and cupper[ionic forms (CuSO4), (Zn SO4) and chelated forms of [Cu Zn (II) HEDTA and Cu (II) HEDTA], whereas, HEDTA is N-(hydroxyethyl) ethylenediamine triacetic acid, applied at micromolar concentrations in the nutrient solution] of Phaseolus Vulgaris plants grown hydroponically under conditions of iron deficiency (- Fe) were investigated. Plant variants (– Fe + 2 µM Cu2+) and (– Fe+ 20 µM Zn2+) with extremely strong chlorosis were examined for investigations to take after the recuperation of leaf greening after treatment with Cu(II)HEDTA created leaf greening in the two variations, particularly strong for the recently which created leaf, as it appeared with chlorophyll estimations. Changes of plasma membrane reductase movement (PMRA) in roots after treatment with ionic or chelated copper were followed in (+Fe) and (– Fe) plants. The results show the increment of ferric-chelate reductase action (with substrate of Fe (III) HEDTA). Then, the cupric-chelate Cu (II) HEDTA, connected at similar level in arrangements with (– Fe) plants, kept up the high encouragement of plasma membrane ferric-chelate reductase activity. It can be concluded that the treatment with Cu (II) HEDTA enhanced the development and root plasma membrane reductase activity (PMRA) and additionally iron deficiency reactions of phaseolus plants. Regard to cell compounds increase, measurements of 20 μM of Zn altogether developed the action of the protein superoxide dismutase and peroxidase.

Two Phases Of Ferricyanide Reductase Activity In Ehrlich Cell Plasma Membranes

1992 ◽  
Vol 47 (11-12) ◽  
pp. 929-931 ◽  
Author(s):  
Antonio del Castillo-Olivares ◽  
Javier Márquez ◽  
Ignacio Núñez de Castro ◽  
Miguel Angel Medina
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Reductase Activity ◽  
Membrane Vesicles ◽  
Plasma Membrane Vesicles ◽  
Cell Plasma Membrane ◽  
Ferricyanide Reductase ◽  
Ehrlich Cell ◽  
Cell Plasma ◽  
Two Phases

Ehrlich cell plasma membrane vesicles have a ferricyanide reductase activity that shows two phases. These two phases were kinetically characterized. Evidence is presented for a differential effect of trypsin on both phases

Root and Leaf Ferric Chelate Reductase Activity in Pond Apple and Soursop

2005 ◽  
Vol 27 (8) ◽  
pp. 1381-1393 ◽  
Author(s):  
Maritza Ojeda ◽  
Bruce Schaffer ◽  
Frederick S. Davies
Keyword(s):  
Reductase Activity ◽  
Ferric Chelate Reductase ◽  
Ferric Chelate Reductase Activity

scholarly journals PREPARATION AND CHARACTERIZATION OF A PLASMA MEMBRANE FRACTION FROM ISOLATED FAT CELLS

1970 ◽  
Vol 44 (2) ◽  
pp. 417-432 ◽  
Author(s):  
Daniel W. McKeel ◽  
Leonard Jarett
Keyword(s):  
Plasma Membrane ◽  
Cytochrome C ◽  
Membrane Fraction ◽  
Plasma Membranes ◽  
Reductase Activity ◽  
Fat Cells ◽  
Isolated Fat Cells ◽  
Adenyl Cyclase Activity ◽  
Cytochrome C Reductase ◽  
Plasma Membrane Fraction

A rapid method of preparing plasma membranes from isolated fat cells is described. After homogenization of the cells, various fractions were isolated by differential centrifugation and linear gradients. Ficoll gradients were preferred because total preparation time was under 3 hr. The density of the plasma membranes was 1.14 in sucrose. The plasma membrane fraction was virtually uncontaminated by nuclei but contained 10% of the mitochondrial succinic dehydrogenase activity and 25–30% of the RNA and reduced nicotinamide adenine dinucleotide cytochrome c reductase activity of the microsomal fraction. Part of the RNA and NADH-cytochrome c reductase activity was believed to be native to the plasma membrane or to the attached endoplasmic reticulum membranes demonstrated by electron microscopy. The adenyl cyclase activity of the plasma membrane fraction was five times that of Rodbell's "ghost" preparation and retained sensitivity to epinephrine. The plasma membrane ATPase activity was five times that of the homogenate and microsomal fractions. Electron microscopic evidence suggested contamination of the plasma membrane fraction by other subcellular components to be less than the biochemical data indicated.

scholarly journals CIPK23 is involved in iron acquisition of Arabidopsis by affecting ferric chelate reductase activity

Plant Science ◽  
2016 ◽  
Vol 246 ◽  
pp. 70-79 ◽  
Author(s):  
Qiuying Tian ◽  
Xinxin Zhang ◽  
An Yang ◽  
Tianzuo Wang ◽  
Wen-Hao Zhang
Keyword(s):  
Reductase Activity ◽  
Iron Acquisition ◽  
Ferric Chelate Reductase ◽  
Ferric Chelate Reductase Activity

scholarly journals ISOLATION OF PLASMA MEMBRANE FRAGMENTS FROM HELA CELLS

1969 ◽  
Vol 41 (2) ◽  
pp. 378-392 ◽  
Author(s):  
Charles W. Boone ◽  
Lincoln E. Ford ◽  
Howard E. Bond ◽  
Donald C. Stuart ◽  
Dianne Lorenz
Keyword(s):  
Plasma Membrane ◽  
Hela Cells ◽  
Plasma Membranes ◽  
Reductase Activity ◽  
Membrane Vesicle ◽  
Membrane Vesicles ◽  
Sucrose Density Gradient ◽  
Plasma Membrane Vesicle ◽  
Whole Cells ◽  
Continuous Sucrose Gradient

A method for isolating plasma membrane fragments from HeLa cells is described. The procedure starts with the preparation of cell membrane "ghosts," obtained by gentle rupture of hypotonically swollen cells, evacuation of most of the cell contents by repeated washing, and isolation of the ghosts on a discontinuous sucrose density gradient. The ghosts are then treated by minimal sonication (5 sec) at pH 8.6, which causes the ghost membranes to pinch off into small vesicles but leaves any remaining larger intracellular particulates intact and separable by differential centrifugation. The ghost membrane vesicles are then subjected to isopycnic centrifugation on a 20–50% w/w continuous sucrose gradient in tris-magnesium buffer, pH 8.6. A band of morphologically homogeneous smooth vesicles, derived principally from plasma membrane, is recovered at 30–33% (peak density = 1.137). The plasma membrane fraction contained a Na-K-activated ATPase activity of 1.5 µmole Pi/hr per mg, 3% RNA, and 13.8% of the NADH-cytochrome c reductase activity of a heavier fraction from the same gradient which contained mitochondria and rough endoplasmic vesicles. The plasma membranes of viable HeLa cells were marked with 125I-labeled horse antibody and followed through the isolation procedure. The specific antibody binding of the plasma membrane vesicle fraction was increased 49-fold over that of the original whole cells.

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