Effect of lysophosphatidylcholine on the NADH-ferricyanide reductase activity associated with the plasma membranes of corn roots

Plant Science ◽  
1990 ◽  
Vol 70 (2) ◽  
pp. 143-153 ◽  
Author(s):  
Isabelle Bourdil ◽  
Marie-Louise Milat ◽  
Jean Pierre Blein
Keyword(s):  
Plasma Membranes ◽  
Reductase Activity ◽  
Ferricyanide Reductase ◽  
Corn Roots

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

DNA precursor pools and ribonucleotide reductase activity: distribution between the nucleus and cytoplasm of mammalian cells

1985 ◽  
Vol 5 (12) ◽  
pp. 3443-3450
Author(s):  
J M Leeds ◽  
M B Slabaugh ◽  
C K Mathews
Keyword(s):  
Cell Cycle ◽  
Ribonucleotide Reductase ◽  
Cho Cells ◽  
Mammalian Cells ◽  
Plasma Membranes ◽  
Reductase Activity ◽  
Cell Activity ◽  
S Phase ◽  
Whole Cell ◽  
Ribonucleotide Reductase Activity

Nuclear and whole-cell deoxynucleoside triphosphate (dNTP) pools were measured in HeLa cells at different densities and throughout the cell cycle of synchronized CHO cells. Nuclei were prepared by brief detergent (Nonidet P-40) treatment of subconfluent monolayers, a procedure that solubilizes plasma membranes but leaves nuclei intact and attached to the plastic substratum. Electron microscopic examination of monolayers treated with Nonidet P-40 revealed protruding nuclei surrounded by cytoskeletal remnants. Control experiments showed that nuclear dNTP pool sizes were stable during the time required for isolation, suggesting that redistribution of nucleotides during the isolation procedure was minimal. Examination of HeLa whole-cell and nuclear dNTP levels revealed that the nuclear proportion of each dNTP was distinct and remained constant as cell density increased. In synchronized CHO cells, all four dNTP whole-cell pools increased during S phase, with the dCTP pool size increasing most dramatically. The nuclear dCTP pool did not increase as much as the whole-cell dCTP pool during S phase, lowering the relative nuclear dCTP pool. Although the whole-cell dNTP pools decreased after 30 h of isoleucine deprivation, nuclear pools did not decrease proportionately. In summary, nuclear dNTP pools in synchronized CHO cells maintained a relatively constant concentration throughout the cell cycle in the face of larger fluctuations in whole-cell dNTP pools. Ribonucleotide reductase activity was measured in CHO cells throughout the cell cycle, and although there was a 10-fold increase in whole-cell activity during S phase, we detected no reductase in nuclear preparations at any point in the cell cycle.

scholarly journals Characterization of membrane polypeptides from pea leaf peroxisomes involved in superoxide radical generation

1999 ◽  
Vol 337 (3) ◽  
pp. 531-536 ◽  
Author(s):  
Eduardo LÓPEZ-HUERTAS ◽  
Francisco J. CORPAS ◽  
Luisa M. SANDALIO ◽  
Luis A. DEL RÍO
Keyword(s):  
Cytochrome C ◽  
Electron Donor ◽  
Polyclonal Antibodies ◽  
Reductase Activity ◽  
Monodehydroascorbate Reductase ◽  
Peroxisomal Membrane ◽  
Cytochrome C Reductase ◽  
Ferricyanide Reductase ◽  
Sds Page ◽  
O2 Production

The production of superoxide radicals (O2-•) and the activities of ferricyanide reductase and cytochrome c reductase were investigated in peroxisomal membranes from pea (Pisum sativum L.) leaves using NADH and NADPH as electron donors. The generation of O2-• by peroxisomal membranes was also assayed in native polyacrylamide gels using an in situ staining method with NitroBlue Tetrazolium (NBT). When peroxisomal membranes were assayed under native conditions using NADH or NADPH as inducer, two different O2-•-dependent Formazan Blue bands were detected. Analysis by SDS/PAGE of these bands demonstrated that the NADH-induced NBT reduction band contained several polypeptides (PMP32, PMP61, PMP56 and PMP18, where PMP is peroxisomal membrane polypeptide and the number indicates molecular mass in kDa), while the NADPH-induced band was due exclusively to PMP29. PMP32 and PMP29 were purified by preparative SDS/PAGE and electroelution. Reconstituted PMP29 showed cytochrome c reductase activity and O2-• production, and used NADPH specifically as electron donor. PMP32, however, had ferricyanide reductase and cytochrome c reductase activities, and was also able to generate O2-• with NADH as electron donor, whereas NADPH was not effective as an inducer. The reductase activities of, and O2-• production by, PMP32 were inhibited by quinacrine. Polyclonal antibodies against cucumber monodehydroascorbate reductase (MDHAR) recognized PMP32, and this polypeptide is likely to correspond to the MDHAR reported previously in pea leaf peroxisomal membranes.

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 Fe3+-Chelate Reductase Activity of Plasma Membranes Isolated from Tomato (Lycopersicon esculentum Mill.) Roots

1991 ◽  
Vol 97 (2) ◽  
pp. 537-544 ◽  
Author(s):  
Marcia J. Holden ◽  
Douglas G. Luster ◽  
Rufus L. Chaney ◽  
Thomas J. Buckhout ◽  
Curtis Robinson
Keyword(s):  
Lycopersicon Esculentum ◽  
Plasma Membranes ◽  
Reductase Activity ◽  
Lycopersicon Esculentum Mill

scholarly journals The (Ca2+ + Mg2+)-stimulated ATPase of the rat parotid endoplasmic reticulum

1986 ◽  
Vol 235 (2) ◽  
pp. 491-498 ◽  
Author(s):  
P Thiyagarajah ◽  
S C Lim
Keyword(s):  
Endoplasmic Reticulum ◽  
Cyclic Amp ◽  
Plasma Membranes ◽  
Specific Activity ◽  
Reductase Activity ◽  
Gradient Centrifugation ◽  
Fold Increase ◽  
Parotid Glands ◽  
Tissue Homogenates ◽  
Rat Parotid

A membrane fraction enriched in endoplasmic reticulum was prepared from rat parotid glands by using sucrose-gradient centrifugation. The fraction showed a 10-fold increase in specific activity of NADPH: cytochrome c reductase activity over that of tissue homogenates and minimal contamination with plasma membranes or mitochondria. The endoplasmic reticulum fraction possessed both Mg2+ -stimulated ATPase as well as Ca2+, Mg2+-ATPase [(Ca2+ + Mg2+)-stimulated ATPase]activity. The Ca2+, Mg2+-ATPase required 2-5 mM-Mg2+ for optimal activity and was stimulated by submicromolar concentrations of free Ca2+. The Km for free Ca2+ was 0.55 microM and the average Vmax. was 60 nmol/min per mg of protein. The Km for ATP was 0.11 mM. Other nucleotides, such as GTP, CTP or ADP, could not substitute for ATP in supporting the Ca2+-activated nucleotidase activity. Increasing the K+ concentration from 0 to 100 mM caused a 2-fold activation of the Ca2+, Mg2+-ATPase. Trifluoperazine, W7 [N-(6-aminohexyl)-5-chloronaphthalene-1-sulphonamide] and vanadate inhibited the enzyme. The concentration of trifluoperazine and vanadate required for 50% inhibition of the ATPase were 52 microM and 28 microM respectively. Calmodulin, cyclic AMP, cyclic AMP-dependent protein kinase and inositol 1,4,5-trisphosphate had no effect on the ATPase. The properties of the Ca2+, Mg2+ -ATPase were distinct from those of the Mg2+-ATPase, but comparable with those reported for the parotid endoplasmic-reticulum Ca2+-transport system [Kanagasuntheram & Teo (1982) Biochem. J. 208, 789-794]. The results suggest that the Ca2+, Mg2+-ATPase is responsible for driving the ATP-dependent Ca2+ accumulation by this membrane.

scholarly journals Ascorbate-mediated transplasma membrane electron transport in pulmonary arterial endothelial cells

1998 ◽  
Vol 274 (5) ◽  
pp. L685-L693 ◽  
Author(s):  
Marilyn P. Merker ◽  
Lars E. Olson ◽  
Robert D. Bongard ◽  
Meha K. Patel ◽  
John H. Linehan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Endothelial Cells ◽  
Plasma Membrane ◽  
Electron Transport ◽  
Electron Acceptor ◽  
Reductase Activity ◽  
Ferricyanide Reductase ◽  
Transplasma Membrane Electron Transport ◽  
Pulmonary Arterial ◽  
Arterial Endothelial Cells

Pulmonary endothelial cells are capable of reducing certain electron acceptors at the luminal plasma membrane surface. Motivation for studying this phenomenon comes in part from the expectation that it may be important both as an endothelial antioxidant defense mechanism and in redox cycling of toxic free radicals. Pulmonary arterial endothelial cells in culture reduce the oxidized forms of thiazine compounds that have been used as electron acceptor probes for studying the mechanisms of transplasma membrane electron transport. However, they reduce another commonly studied electron acceptor, ferricyanide, only very slowly by comparison. In the present study, we examined the influence of ascorbate [ascorbic acid (AA)] and dehydroascorbate [dehydroascorbic acid (DHAA)] on the ferricyanide and thiazine reductase activities of the bovine pulmonary arterial endothelial cell surface. The endothelial cells were grown on microcarrier beads so that the reduction of ferricyanide and methylene blue could be studied colorimetrically in spectrophotometer cuvettes and in flow-through cell columns. The ferricyanide reductase activity could be increased 80-fold by adding DHAA to the medium, with virtually no effect on methylene blue reduction. The DHAA effect persisted after the DHAA was removed from the medium. AA also stimulated the ferricyanide reductase activity but was less potent, and the relative potencies of AA and DHAA correlated with their relative rates of uptake by the cells. The results are consistent with the hypothesis that AA is an intracellular electron donor for an endothelial plasma membrane ferricyanide reductase and that the stimulatory effect of DHAA is the result of increasing intracellular AA. Adding sufficient DHAA to markedly increase extracellular ferricyanide reduction had little effect on the plasma membrane methylene blue reductase activity, suggesting that pulmonary arterial endothelial cells have at least two separate transplasma membrane electron transport systems.

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.

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