Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| an improved method for the isolation of spinach chloroplast envelope membranes. | a three-phase, discontinuous sucrose gradient yielded two distinct fractions of envelope membranes from spinach (spinacia oleracea l.) chloroplasts. their buoyant densities were 1.08 g cm(-3) and 1.11 g cm(-3). electron micrographs showed the lighter and heavier fractions to consist primarily of single and double membranes, respectively. the milligrams of lipid-milligrams of protein ratio for the complete envelope membrane (double membrane fraction) was 1.74. thin layer chromatograms showed that ... | 1974 | 16658971 |
| properties of glucosyltransferase and glucan transferase from spinach. | a glucosyl and a glucosyl-glucan transferase activity from spinach (spinacia oleracea l. var. matador) leaves have been partially purified and characterized. the latter activity (fraction 1 after diethylaminoethylcellulose chromatography) is responsible for the transfer of glucosyl as well as of maltosyl, maltotriosyl, and higher homologous residues to glucose giving rise to maltose and the correspondingly larger molecules. this fraction also shows beta-amylase activity. the transfer takes place ... | 1974 | 16658965 |
| photosynthetic activity of spinach chloroplasts after isopycnic centrifugation in gradients of silica. | chloroplast suspensions from spinach (spinacia oleracea l.) were clearly resolved into intact and stripped chloroplasts by isopycnic centrifugation in density gradients of silica sol ("ludox") and polyethlene glycol. the intact chloroplasts fixed co(2) and evolved o(2) more rapidly than the crude suspensions; the stripped chloroplasts were inactive. during the photosynthetic fixation of (14)co(2) in the intact chloroplasts recovered from the gradient, the (14)c label was observed to spread throu ... | 1974 | 16658922 |
| uptake of bicarbonate ion in darkness by isolated chloroplast envelope membranes and intact chloroplasts of spinach. | bicarbonate uptake by isolated chloroplast envelope membranes and intact chloroplasts of spinach (spinacia oleracea l. var. viroflay) in darkness exhibited a similar dependency upon temperature, ph, time, and concentrations of isolated or attached envelope membranes. this similarity in uptake properties demonstrates the usefulness of the envelope membranes for the study of chloroplast permeability. maximal rates for dark hco(3) (-) uptake by isolated envelope membranes and intact chloroplasts we ... | 1974 | 16658920 |
| fat metabolism in higher plants: lxii. stearl-acyl carrier protein desaturase from spinach chloroplasts. | stearyl-acyl carrier protein desaturase (ec 1.14.99.6), present in the stroma fraction of spinach (spinacia oleracea) chloroplasts, rapidly desaturated enzymatically prepared stearyl-acyl carrier protein to oleic acid. no other substrates were desaturated. in addition to stearyl-acyl carrier protein, reduced ferredoxin was an essential component of the system. the electron donor systems were either ascorbate, dichlorophenolindophenol, photosystem i and light, or nadph and ferredoxin-nadp reducta ... | 1974 | 16658913 |
| dependence of nitrite reduction on electron transport chloroplasts. | methyl viologen and phenazine methosulfate (photosystem i electron acceptors), 3-(3,4-dichlorophenyl)-1, 1-dimethylurea (dcmu, electron-transport inhibitor), and methylamine (photophosphorylation uncoupler) were used to study the dependence of nitrite reduction on electron transport in chloroplasts.dcmu, methyl viologen, and phenazine methosulfate markedly inhibited, whereas methylamine stimulated no(2) (-) reduction in isolated, intact spinach (spinacia oleracea l.) chloroplasts. the addition o ... | 1974 | 16658912 |
| immunological and biochemical studies on isozymes of malate dehydrogenase and citrate synthetase in castor bean glyoxysomes. | rabbit gamma-globulin obtained after the injection of solubilized proteins of castor bean (ricinus communis l var. hale) glyoxysomes contains antibodies against some of the glyoxysomal enzymes. the gamma-globulin was shown to inhibit by 50% and 80%, respectively, the in vitro activities of the castor bean glyoxysomal citrate synthetase and malate dehydrogenase. the conditions required for the inactivation are described.the glyoxysomal and mitochondrial citrate synthetase from castor bean endospe ... | 1974 | 16658889 |
| isolation of intact plastids from a range of plant tissues. | a technique for the isolation of intact plastids from spinach (spinacia oleracea) and pea (pisum sativum) leaves, pea roots and castor bean (ricinus communis) endosperm is described. this technique involves brief centrifugation of whole homogenates on density gradients. intact plastids were located in the gradient by assaying for triose phosphate isomerase activity. contamination of the plastic peak with mitochondria and microbodies was estimated by measurement of cytochrome oxidase and catalase ... | 1974 | 16658807 |
| relationship between the level of adenine nucleotides and the carboxylation activity of illuminated isolated spinach chloroplasts: a study with antimycin a. | the changes in the levels of intact spinach (spinacia oleracea l.) chloroplast adenine nucleotides during the time course of light-dependent co(2) fixation were determined with respect to the effect of antimycin a. this study demonstrated that antimycin a lowered the rate of atp formation during the induction period of carboxylation. while the steady state levels of atp and the energy-charge value also decreased in the presence of antimycin, the concomitant increase of the co(2) fixation activit ... | 1974 | 16658804 |
| phosphoenolpyruvate carboxylase from spinach leaf tissue: inhibition by sulfite ion. | phosphoenolpyruvate carboxylase (ec 4.1.1.31), partially purified from spinach (spinacia oleracea) leaves, is inhibited by so(3) (2-) ion. the inhibition is competitive or mixed type with respect to hco(3) (-) (ki = 17 mm), and noncompetitive with respect to phosphoenolpyruvic acid (ki = 11 mm), mg(2+) (ki = 10 mm), and mn(2+) (ki = 2.4 mm). the inhibitory effect of so(3) (2-) is more significant in the presence of mn(2+) than in the presence of mg(2+). l-malate, an inhibitor of phosphoenolpyruv ... | 1974 | 16658799 |
| the azolla, anabaena azollae relationship: i. initial characterization of the association. | cultures of azolla caroliniana willd. free of the symbiotic blue-green alga, anabaena azollae, were obtained by treatment of azolla fronds with a regimen of antibiotics. these symbiontfree plants can be maintained only on medium containing a combined nitrogen source.morphological aspects of the symbiotic association show the confinement of the anabaena azollae within the leaf cavity of the azolla. procedures were established for the isolation of pure preparations of anabaena azollae and azolla c ... | 1974 | 16658796 |
| the role of galactolipids in spinach chloroplast lamellar membranes: i. partial purification of a bean leaf galactolipid lipase and its action on subchloroplast particles. | a galactolipid lipase has been isolated and partially purified from the chloroplast fraction of the primary leaves of phaseolus vulgaris var. kentucky wonder. the lipase hydrolyzed monogalactosyl diglyceride rapidly and phosphatidyl choline relatively slowly. triolein and p-nitrophenyl stearate were not hydrolyzed.spinach subchloroplast particles were excellent substrates for the lipase. initial rates of fatty acid release from subchloroplast particles at 30 c by the lipase as high as 60 microeq ... | 1974 | 16658772 |
| levels of (+/-) abscisic acid and xanthoxin in spinach under different environmental conditions. | the levels of the growth inhibitors(+)-abscisic acid and xanthoxin were determined in the long day plant spinach (spinacia oleracea l. cv. savoy hybrid 612) grown under different environmental conditions. when plants were transferred from light to darkness, the (+)-abscisic acid level always decreased, whereas the xanthoxin content did not change. the (+)-abscisic acid content was higher in plants grown under low than under high relative humidity.xanthoxin levels were not affected by photoperiod ... | 1974 | 16658759 |
| nitrite assimilation and amino nitrogen synthesis in isolated spinach chloroplasts. | the assimilation of nitrite leading to de novo synthesis of amino nitrogen in a chloroplast-enriched fraction isolated from freshly harvested young spinach (spinacia oleracea l.) leaves was demonstrated. the preparations showed approximately 55% intact chloroplasts as determined by light scattering properties and fixed co(2) at rates of approximately 100 mumoles hr(-1) mg chlorophyll(-1).the chloroplast-enriched fraction contained the enzymes, nitrite reductase and nadph-glutamate dehydrogenase, ... | 1974 | 16658715 |
| further studies on the bicarbonate stimulation of photophosphorylation in isolated chloroplasts. | the bicarbonate effect in stimulating the rate of photophosphorylation by isolated spinach (spinacia oleracea var. virginia blight-resistant savoy) chloroplasts at a ph below the optimum has been re-examined. its seasonal nature may be related to the hormonal status of the plants. bicarbonate anions stimulate adenosine 5'-triphosphate synthesis if added in the final, adenosine 5'-triphosphate-forming stage of either a postillumination or an acid-base experiment. they also stimulate the membrane- ... | 1974 | 16658679 |
| biosynthesis of phosphatidylethanolamine by enzyme preparations from plant tissues. | the enzymic utilization of cytidine diphosphoethanolamine in the synthesis of phosphatidylethanolamine is localized in the microsomal fraction of spinach (spinacia oleracea) leaves. the metal ion requirement can be satisfied by mn(2+) (saturation approximately 0.6 mm) or mg(2+) (saturation approximately 25 mm). the enzyme has a ph optimum of 8.0 in the presence of mn(2+) and 7.5 in the presence of mg(2+). a michaelis constant of 20 mum was determined for cytidinediphos-phoethanolamine. enzyme ac ... | 1974 | 16658671 |
| carbon dioxide fixation in the light and in the dark by isolated spinach chloroplasts. | factors affecting co(2) fixation in the spinach (spinacia oleracea) chloroplast were investigated. free magnesium ions are shown to be highly inhibitory for photosynthetic co(2) fixation in isolated intact spinach chloroplasts. the ph optimum for co(2) fixation is about 8.5 but is dependent upon the reaction medium. conditions are defined under which chloroplasts illuminated in the absence of co(2) accumulate ribulose 1,5-diphosphate, and fix co(2) in a subsequent dark period when high magnesium ... | 1974 | 16658664 |
| properties of phosphoribulokinase of whole chloroplasts. | the ability of intact spinach (spinacia oleracea) chloroplast preparations to catalyze co(2) fixation and photophosphorylation was examined. under conditions optimal for co(2) fixation, only poor photophosphorylation was observed. conditions optimal for photophosphorylation were found to be highly inhibitory to the co(2)-fixing capacity of the intact chloroplast preparation.a method for following the activity of phosphoribulokinase in the intact chloroplast preparation was developed, and conditi ... | 1974 | 16658663 |
| site-specific inhibition of photophosphorylation in isolated spinach chloroplasts by mercuric chloride. | photophosphorylation associated with noncyclic electron transport in isolated spinach (spinacia oleracea) chloroplasts is inhibited to approximately 50% by low concentrations of hgcl(2) (less than 1 mumole hg(2+)/mg chlorophyll) when the electron transport pathway includes both sites of energy coupling. reactions involving only a part of the electron transport system can give a functional isolation of at least two sites coupled to phosphorylation. only one of these sites, located between the oxi ... | 1973 | 16658631 |
| zinc deficiency, carbonic anhydrase, and photosynthesis in leaves of spinach. | a shortage in the zinc supply to spinach (spinacia oleracea l.) drastically reduced carbonic anhydrase levels with little effect on net co(2) uptake per unit leaf area, except with the most severe zinc stresses. under these conditions, carbonic anhydrase was below 10% and photosynthesis 60 to 70% of the control levels. when photosynthesis was measured at a range of co(2) supply levels, zinc-deficient leaves were less efficient at 300 to 350 microliters per liter co(2) and above, but the same as ... | 1973 | 16658536 |
| fat metabolism in higher plants: lvii. a comparison of fatty acid-synthesizing enzymes in chloroplasts isolated from mature and immature leaves of spinach. | chloroplasts isolated from immature leaves of spinach (spinacia oleracea) differ in enzyme levels from those isolated from mature leaves. on a chlorophyll basis, immature chloroplast preparations had 5- to 6-fold higher capacity to synthesize fatty acids from 2-(14)c-acetate compared to plastids isolated from mature leaves. this difference was correlated with higher activities for the enzymes, acetyl coenzyme a synthetase, malonyl coenzyme a synthetase, acetyl coenzyme a carboxylase, and oleyl c ... | 1973 | 16658518 |
| response of carbon dioxide fixation to water stress: parallel measurements on isolated chloroplasts and intact spinach leaves. | application of water stress to isolated spinach (spinacia oleracea) chloroplasts by redutcion of the osmotic potentials of co(2) fixation media below -6 to -8 bars resulted in decreased rates of fixation regardless of solute composition. a decrease in co(2) fixation rate of isolated chloroplasts was also found when leaves were dehydrated in air prior to chloroplast isolation. an inverse response of co(2) fixation to osmotic potential of the fixation medium was found with chloroplasts isolated fr ... | 1973 | 16658493 |
| isocitrate lyase in green leaves. | isocitrate lyase (ec 4.1.3.1) has been demonstrated in crude dialyzed extracts of healthy spinach (spinacia oleracea) leaves from commercial sources and wheat (triticum aestivum) and maize (zea mays) leaves stored in darkness in the cold room for 1 week. the products of the reaction were identified as glyoxylate and succinate, the former by its phenylhydrazone, and the latter traced by isotopic labeling and cochromatography. fresh spinach extracts contain a mixture of at least two endogenous inh ... | 1973 | 16658428 |
| differences in lipid composition between undifferentiated and mature maize chloroplasts. | lipid compositions of undifferentiated maize (zea mays) chloroplasts, capable of fixing co(2), were compared with the lipid compositions of mature chloroplasts, which do not fix co(2), located in both the mesophyll and bundle sheath cells. the major lipids found in all three chloroplast types were the glycolipids, monogalactosyl diglyceride and digalactosyl diglyceride, followed by decreasing amounts of sulfolipid, phosphatidyl glycerol, phosphatidyl choline, phosphatidyl inositol, and diphospha ... | 1973 | 16658413 |
| carotenoid composition of spinach chloroplast grana and stroma lamellae. | stroma lamellae and grana stacks prepared by french press rupture of spinach (spinacia oleracea) chloroplasts contain similar amounts of beta-carotene on a protein basis. the grana fraction has considerably more xanthophylls than does the stroma fraction. total carotenoid to chlorophyll ratios are similar for both fractions. | 1973 | 16658372 |
| activation of polyphenol oxidase of chloroplasts. | polyphenol oxidase of leaves is located mainly in chloroplasts isolated by differential or sucrose density gradient centrifugation. this activity is part of the lamellar structure that is not lost on repeated washing of the plastids. the oxidase activity was stable during prolonged storage of the particles at 4 c or -18 c. the km (dihydroxyphenylalanine) for spinach leaf polyphenol oxidase was 7 mm by a spectrophotometric assay and 2 mm by the manometric assay. polyphenol oxidase activity in the ... | 1973 | 16658308 |
| isolation from rhizobium for factors which transfer electrons to soybean nitrogenase. | rhizobium japonicum grown anaerobically with nitrate produced several factors capable of transferring electrons from spinach chloroplasts lacking photosystem ii to soybean root nodule nitrogenase. the same organism grown aerobically produced no factors with detectable activity. it is concluded that the bacterium is potentially capable of producing these proteins in the low oxygen conditions of the leguminous root nodule. | 1973 | 16658274 |
| reversible abolition of enhancement in isolated spinach chloroplasts. | the photosynthetic evolution of oxygen by isolated chloroplasts of spinacia oleracea l. was studied using a modulated oxygen electrode. the enhancement effect, measured as the increase in the relative quantum yield of 650-nanometer light due to the presence of 710-nanometer light, was profoundly influenced by the concentration of inorganic cations in the bathing medium. chloroplast fragments immersed in a solution containing a very low concentration of mgcl(2) or kcl, did not display enhancement ... | 1972 | 16658263 |
| acid-bath phosphorylation in heptane-extracted chloroplasts. | when spinach (spinacia oleracea) chloroplast fragments were lyophilized and extracted with n-heptane, acid-bath phosphorylation was significantly reduced. phosphorylation could be restored to these chloroplasts, if the extracted material (containing quinones, carotenoids, and other lipids) was added back to dry preparation before rehydration. the results reported suggest it was not quinones which were required for restoration of acid-bath phosphorylation but lipids. it is suggested that the lipi ... | 1972 | 16658223 |
| the distribution of carbonic anhydrase and ribulose diphosphate carboxylase in maize leaves. | extraction of maize (zea mays) leaves by progressive grinding under suitably protective conditions yields total carbonic anhydrase activities (4800 units per milligram chlorophyll) comparable to the activity in spinach (spinacia oleracea) leaves. the total ribulose diphosphate carboxylase activity was also equal to or greater than the best literature values for maize. of the total leaf carbonic anhydrase, 72.5% on a chlorophyll basis was present in the mesophyll cells and 14.2% in the bundle-she ... | 1972 | 16658170 |
| microbody enzymes and carboxylases in sequential extracts from c(4) and c(3) leaves. | a seven-step sequential grinding procedure was applied to leaves of atriplex rosea, sorghum sudanense, and spinacia oleracea to study the distribution of carboxylases and microbody enzymes. in the extracts from c(4) species there were 7- to 10-fold reciprocal changes in specific activities of ribulose-1, 5-diphosphate carboxylase and phosphoenolpyruvate carboxylase. no such changes occurred in sequential extracts from spinach. no inhibitors of ribulose-1, 5-diphosphate carboxylase were detected ... | 1972 | 16658149 |
| antimycin a stimulation of rate-limiting steps of photosynthesis in isolated spinach chloroplasts. | changes in levels of metabolites in isolated spinach (spinacia oleracea) chloroplasts seen upon addition of antimycin a suggest that the activities of enzymes mediating several regulated reactions are affected. apparently, the presence of added antimycin a does not increase the level of co(2) in the chloroplasts, nor does it stimulate co(2) fixation by increasing the level of the carboxylation substrate, ribulose-1,5-diphosphate. rather, it appears that antimycin a increases co(2) fixation rate ... | 1972 | 16657971 |
| studies on effect of certain quinones: i. electron transport, photophosphorylation, and co(2) fixation in isolated chloroplasts. | the effect of quinone herbicides and fungicides on photosynthetic reactions in isolated spinach (spinacia oleracea) chloroplasts was investigated. 2,3-dichloro-1,4-naphthoquinone (dichlone), 2-amino-3-chloro-1,4-naphthoquinone (06k-quinone), and 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil) inhibited ferricyanide reduction as well as atp formation. benzoquinone had little or no effect on these reactions. the two reactions showed a differential sensitivity to these inhibitors. dichlone was a s ... | 1972 | 16657965 |
| inhibition of chloroplast reactions with phenylmercuric acetate. | phenylmercuric acetate is a selective inhibitor of the photosynthetic activities of isolated spinach (spinacia oleracea) chloroplasts. at 5 mum concentration of phenylmercuric acetate, photophosphorylation is inhibited. at 33 mum phenylmercuric acetate, ferredoxin is inactivated. ferredoxin-nadp oxidoreductase is 50% inhibited at 100 mum phenylmercuric acetate. photosystem ii reactions are 50% inhibited at 150 mum phenylmercuric acetate and very much higher cooncentrations-500 mum-are needed to ... | 1972 | 16657964 |
| involvement of photosynthetic carbon reduction cycle intermediates in co(2) fixation and o(2) evolution by isolated chloroplasts. | the photosynthetic carbon reduction cycle intermediates can be divided into three classes according to their effects on the rate of photosynthetic co(2) evolution by whole spinach (spinacia oleracea) chloroplasts and on their ability to affect reversal of certain inhibitors (nigericin, arsenate, arsenite, iodoacetate, antimycin a) of photosynthesis: class i (maximal): fructose 1, 6-diphosphate, dihydroxyacetone phosphate, glyceraldehyde-3-phosphate, ribose-5-phosphate; class 2 (slight): glucose ... | 1971 | 16657865 |
| inhibition of photosynthetic carbon dioxide fixation in isolated spinach chloroplasts exposed to reduced osmotic potentials. | reduced osmotic potentials inhibited the rate of co(2) fixation by isolated intact spinach (spinacia oleracea) chloroplasts. this inhibition was observed immediately after transfer of chloroplasts from a solution containing 0.33 m sorbitol to higher sorbitol concentrations, and the depressed rate remained constant. the inhibited co(2) fixation could not be attributed to a decreased rate of photosynthetic electron transport, since nadp reduction was unaffected by subjecting the chloroplasts to lo ... | 1971 | 16657842 |
| 3-phosphoglycerate phosphatase in plants: iii. activity associated with starch particles. | a particulate form of 3-phosphoglycerate phosphatase represents about 20% of this activity in spinach (spinacia oleracea var. longstanding bloomsdale) leaves. by differential and isopycnic sucrose density gradient centrifugation, all the particulate activity was found in starch grains that pelleted through 2.5 m sucrose. this particulate phosphatase was extremely stable, had a ph optimum of 5.8, and an apparent michaelis constant (3-phosphoglycerate) of 9 x 10(-4)m. no cation requirement for act ... | 1971 | 16657823 |
| effect of antimycin a on photosynthesis of intact spinach chloroplasts. | low concentrations (0.5-10 mum) of antimycin a were shown to increase the rate of co(2) fixation, o(2) evolution and inorganic phosphate esterification in intact spinach (spinacia oleracea) chloroplasts. the increase was highest when the light intensity was saturating. stimulation was independent of the bicarbonate concentration and was accompanied by an enhancement in the synthesis of glycerate 3-phosphate with a decrease in dihydroxyacetone phosphate. the antibiotic decreased the michaelis con ... | 1971 | 16657816 |
| inhibition of glycolipid biosynthesis in chloroplasts by ozone and sulfhydryl reagents. | the metabolism of uridine 5'-pyrophosphate-galactose by spinach (spinacia oleracea) chloroplast preparations was inhibited by ozone. the formation of digalactosyl diglyceride and trigalactosyl diglyceride was inhibited much more than the formation of monogalactosyl diglyceride, steryl glycoside, and acylated steryl glycoside. essentially identical results were obtained when glycolipid synthesis was inhibited by n-ethyl maleimide, p-hydroxymercuribenzoate, and cdcl(2). iodoacetate and iodoacetami ... | 1971 | 16657793 |
| the effect of freezing on thylakoid membranes in the presence of organic acids. | the effect of salts of organic acids on washed and non-washed chloroplast membranes during freezing was investigated. thylakoids were isolated from spinach leaves (spinacia oleracea l.) and, prior to freezing, salts of various organic acids or inorganic salts or both were added. freezing occurred for 3 to 4 hours at -25 c. after thawing membrane integrity was investigated by measuring the activity of cyclic photophosphorylation.at very low nacl levels (1 to 3 mm, washed thylakoids) salts of orga ... | 1971 | 16657754 |
| (+)-abscisic acid content of spinach in relation to photoperiod and water stress. | levels of (+)-abscisic acid present in the long-day plant spinach (spinacia oleracea l., cv. savoy hybrid 612) grown under different photoperiodic regimes were measured in purified extracts by optical rotary dispersion. when plants were transferred from short to long days, the abscisic acid content increased 2- to 3-fold. this rise in the level of abscisic acid took place during the 1st long day. abscisic acid levels of plants under short days as well as under long-day conditions were higher at ... | 1971 | 16657741 |
| effects of photoperiod on growth rate and endogenous gibberellins in the long-day rosette plant spinach. | the earliest visible responses of spinach plants (spinacia oleracea l., cv. savoy hybrid 612) transferred from short to long days (8 hours of high intensity light supplemented with 16 hours of low intensity illumination from incandescent lamps) were upright leaf orientation and increased elongation of the petioles. the effect of long days on growth rate was direct; i.e., there was no after-effect if the plants were transferred to short days. gibberellin a(3) applied to plants under short days ha ... | 1971 | 16657712 |
| isolation of mesophyll cells and bundle sheath cells from digitaria sanguinalis (l.) scop. leaves and a scanning microscopy study of the internal leaf cell morphology. | a technique is described for the separation of mesophyll and bundle sheath cells from digitaria sanguinalis leaves and evidence for separation is given with light and scanning electron micrographs. gentle grinding of fully differentiated leaves in a mortar releases mesophyll cells which are isolated on nylon nets by filtration. more extensive grinding of the remaining tissue yields bundle sheath strands which are isolated by filtration with stainless steel sieves and nylon nets. further grinding ... | 1971 | 16657571 |
| a lipid requirement for photosystem i activity in heptane-extracted spinach chloroplasts. | a lipid requirement for photosystem i activity in spinacia oleracea chloroplasts has been characterized. the transfer of electrons from tetramethyl-p-phenylenediamine through the chloroplast photosystem to viologen dye was used as an assay of photosystem i activity. activity is diminished by prolonged heptane extraction and is partially restored by readdition of the extracted lipid. extracted chloroplasts require plastocyanin for maximal restoration of activity. the effect of lipid extract in re ... | 1971 | 16657568 |
| some effects of triton x-100 on pea etioplasts. | when pea etioplast preparations were treated with triton x-100, the membranes disappeared, the pigments were solubilized, and the organelles appeared to disintegrate. low speed centrifugation (2000g) of the preparations following treatment with triton x-100 resulted in a pellet which contained considerable quantities of plastid material. this included rna polymerase and dna polymerase activity, much of the dna, about 30% of the rna, and 50% of the protein of the washed plastid. the amount of rna ... | 1970 | 16657482 |
| photophosphorylation during chloroplast development in red kidney bean. i. characterization of the mature system and the effect of bsa and sulfhydryl reagents. | optimal conditions were determined for photophosphorylation and reduction in mature chloroplasts from phaseolus vulgaris var. red kidney. bovine serum albumin (bsa) at 1 mg/ml and various sulfhydryl reagents (0.1-0.5 mm) greatly enhanced cyclic and noncyclic phosphorylation, but had little effect on photoreduction. bsa and reduced glutathione also stimulated cyclic phosphorylation in spinach chloroplasts. bsa was needed in the reaction from the start to provide high rates of phosphorylation. bsa ... | 1969 | 16657234 |
| on the molecular identity of esr signal ii observed in photosynthetic systems: the effect of heptane extraction and reconstitution with plastoquinone and deuterated plastoquinone. | speculation as to the identity of signal ii, the light-induced, broad, slow decaying electron spin resonance signal with hyperfine structure observed in photosynthetic materials, has tended to center on the semiquinone of plastoquinone. experiments reported here were designed to give direct evidence bearing on that speculation. heptane extraction of lipids from lyophilized spinach and tobacco chloroplast fragments reduced the amplitude of signal ii and increased the ratio of signal i:signal ii. ... | 1969 | 16657222 |
| inhibition of photosynthesis by oxygen in isolated spinach chloroplasts. | the inhibition of photosynthetic co(2) fixation by o(2), commonly referred to as the warburg effect, was examined in isolated intact spinach (spinacia oleracea) chloroplasts. the major characteristics of this effect in isolated chloroplasts are rapid reversibility when o(2) is replaced by n(2), an increased inhibition by o(2) at low concentrations of co(2) and a decreased effect of o(2) with increased concentrations of co(2).both the dpn- and tpn-linked glyceraldehyde 3-phosphate dehydrogenases ... | 1969 | 16657176 |
| photosynthetic light reactions in chemically fixed anacystis nidulans, chlorella pyrenoidosa, and porphyridium cruentum. | the photochemical activities of various species of unicellular algae (anacystis nidulans, chlorella pyrenoidosa, and porphyridium cruentum) were studied following chemical fixation. fixation with formaldehyde and glutaraldehyde yielded cells which retained their ability to perform photosystem i and photosystem ii reactions. the photochemical efficiencies of some fixed algae are as great as those of unfixed spinach chloroplasts. fixed algae containing accessory pigments appear to be useful models ... | 1969 | 16657097 |
| enzyme activities of the carbon reduction cycle in some photosynthetic organisms. | profile analyses of the enzymes comprising the photosynthetic carbon reduction cycle have been performed in extracts of dark grown and greening euglena gracilis var. bacillaris. chlorella pyrenoidosa grown photoautotrophically, in the light with glucose or in the dark with glucose, tolypothrix tenuis, chromatium and leaves of spinach. amounts of activity are compared with the level of photosynthetic co(2) fixation. only in chromatium were all enzyme activities sufficient to support the in vivo r ... | 1969 | 16657059 |
| biogenesis of oxalate in plant tissues. | red beet root discs aerated in potassium phosphate for 2 to 3 days and young spinach leaves actively produce oxalate. a series of labeled compounds was supplied to each of these tissues to determine the extent of conversion to oxalate. similar results were obtained with the 2 tissues except that in the leaf tissue glyoxylate and glycolate were outstandingly good precursors. carbon from glucose, acetate, and particularly from some acids of the tricarboxylic acid cycle was recovered in oxalate. ex ... | 1968 | 16656975 |
| oxygen evolution and the permeability of the outer envelope of isolated whole chloroplasts. | a rapid oxygraph method of studying the permeability of the envelope of isolated chloroplasts was used. the outer envelope of aqueously isolated whole spinach (spinacia oleracea l.) chloroplasts in buffer is readily permeable to 3-phosphoglyceric acid, which induces an immediate light dependent oxygen evolution. this light dependent oxygen evolution was completely eliminated by swelling these plastids in an osmotically dilute solution. exogenous adenosine diphosphate, but not inorganic phosphate ... | 1968 | 16656943 |
| role of aldolase in photosynthesis. ii demonstration of aldolase types in photosynthetic organisms. | spinach leaves and photoautotrophically grown euglena and chlorella possess fructose 1,6-diphosphate aldolases inhibited by p-chloromercuribenzoate but insensitive to k(+) or ethylenediamine tetraacetate (type i). dark grown euglena and chlorella have aldolases inhibited by p-chloromercuribenzoate and ethylenediamine tetraacetate but stimulated by k(+) (type ii). the red alga, chondrus, and the golden-brown alga, ochromonas, appear to possess both types. bean, pea, and spinach seeds and the leav ... | 1968 | 16656841 |
| chloroplast integrity and atp-dependent co(2) fixation in spinacia oleracea. | washed whole chloroplasts of spinacia oleracea isolated and assayed in a tris (hydroxymethyl aminomethane)-hcl buffered sucrose solution exhibited low dark co(2) fixing activity, whereas washed whole chloroplasts isolated in the same buffer but assayed in that buffer without sucrose exhibited much greater dark co(2) fixing activity. the lowered activity could be attributed to the impermeability of the chloroplast membrane to ribose-5-phosphate or adenosine triphosphate. the preservation of the i ... | 1967 | 16656658 |
| photoinhibition of chloroplast reactions. i. kinetics and action spectra. | a study was made of photoinhibition of spinach chloroplast reactions. the kinetics and spectral characteristics of the photoinhibition over a range between 230 and 700 mmu have been examined. the decline of activity due to preillumination was independent of wavelength, and dependent upon the number of quanta applied, not upon the rate of application. the effectiveness spectra of photoinhibition indicate that active ultraviolet light is absorbed by a pigment which is not a normal light absorber f ... | 1966 | 16656345 |
| effect of salts and electron transport on the conformation of isolated chloroplasts. i. light-scattering and volume changes. | whole chloroplasts isolated from the leaves of spinach (spinacia oleracea l.) exhibit 2 types of conformational change during electron transport. amine-uncoupled chloroplasts swell and atebrin-uncoupled chloroplasts shrink. chloroplasts uncoupled by carbonylcyanide phenylhydrazones and by treatment with ethylenediamine tetraacetic acid do not change their volumes or light-scattering properties during electron transport. phosphorylating chloroplasts shrink only slightly.the rate and extent of the ... | 1966 | 16656285 |
| light-dependent conversions of endogenous alpha-tocopherylquinone and plastoquinone-d in spinacia oleracea chloroplasts. | 1964 | 16655875 | |
| photosystem ii core phosphorylation heterogeneity, differential herbicide binding, and regulation of electron transfer in photosystem ii preparations from spinach. | the effect of photosystem ii core phosphorylation on the secondary quinone acceptor of photosystem ii (q(b)) domain environment was analyzed by comparative herbicide-binding studies with photosystem ii preparations from spinach (spinacia oleracea l.). it was found that phosphorylation reduces the binding affinity for most photosynthetic herbicides. the binding of synthetic quinones and of the electron acceptor 2,6-dichlorophenolindophenol is also reduced by photosystem ii phosphorylation. four p ... | 1992 | 16653222 |
| species-dependent variation in the interaction of substrate-bound ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) and rubisco activase. | purified spinach (spinacea oleracea l.) and barley (hordeum vulgare l.) ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) activase supported 50 to 100% activation of substrate-bound rubisco from spinach, barley, wheat (triticum aestivum l.), soybean (glycine max l.), pea (pisum sativum l.), arabidopsis thaliana, maize (zea mays l.), and chlamydomonas reinhardtii but supported only 10 to 35% activation of rubisco from three solanaceae species, tobacco (nicotiana tabacum l.), petunia (petu ... | 1992 | 16653209 |
| distinctive responses of ribulose-1,5-bisphosphate carboxylase and carbonic anhydrase in wheat leaves to nitrogen nutrition and their possible relationships to co(2)-transfer resistance. | the amounts of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco), total chlorophyll (chl), and total leaf nitrogen were measured in fully expanded, young leaves of wheat (triticum aestivum l.), rice (oryza sativa l.), spinach (spinacia oleracea l.), bean (phaseolus vulgaris l.), and pea (pisum sativum l.). in addition, the activities of whole-chain electron transport and carbonic anhydrase were measured. all plants were grown hydroponically at different nitrogen concentrations. although ... | 1992 | 16653191 |
| biochemical characterization of photosystem ii antenna polypeptides in grana and stroma membranes of spinach. | the photosystem (ps) ii antenna system comprises several biochemically and spectroscopically distinct complexes, including light-harvesting complex ii (lhcii), chlorophyll-protein complex (cp) 29, cp26, and cp24. lhcii, the most abundant of these, is both structurally and functionally diverse. the photosynthetic apparatus is laterally segregated within the thylakoid membrane into psi-rich and psii-rich domains, and the distribution of antenna complexes between these domains has implications for ... | 1992 | 16653152 |
| regulation of sucrose phosphate synthase by gibberellins in soybean and spinach plants. | exogenous applications of gibberellins (gas) increased the extractable activity of leaf sucrose phosphate synthase (sps) in soybean (glycine max [l.]) and spinach (spinacia oleracea [l.]). the response to ga applications was detectable within 2 h postapplication and was still observed 6 h, 24 h, and 7 d after treatment. when paclobutrazol, a ga biosynthesis inhibitor, was applied to intact soybean and spinach plants, decreased extractable sps activity resulted within 24 h following the treatment ... | 1992 | 16653111 |
| expression of the large atp synthase gene cluster in spinach plastids during light-induced development. | the large atp synthase gene cluster in spinach (spinacia oleracea) plastids encodes four of the six chloroplast-encoded atp synthase subunits. expression of this cluster was examined to determine its response to light-induced plastid development. spinach plastid transcripts were isolated from etiolated tissues, etiolated tissues exposed to 24 h of light, young (1-3 cm) leaves, and mature (8-10 cm) leaves. transcript levels were examined from each developmental stage as a function of either the q ... | 1992 | 16653100 |
| flow cytometry of spinach chloroplasts : determination of intactness and lectin-binding properties of the envelope and the thylakoid membranes. | intact spinach (spinacia oleracea) chloroplasts, thylakoid membranes, and inside-out or right-side-out thylakoid vesicles have been characterized by flow cytometry with respect to forward angle light scatter, right angle light scatter, and chlorophyll fluorescence. analysis of intact chloroplasts with respect to forward light scatter and the chlorophyll fluorescence parameter revealed the presence of truly "intact" and "disrupted" chloroplasts. the forward light scatter parameter, normally consi ... | 1992 | 16653090 |
| regulation of plant fatty acid biosynthesis : analysis of acyl-coenzyme a and acyl-acyl carrier protein substrate pools in spinach and pea chloroplasts. | in previous work (d. post-beittenmiller, j.g. jaworski, j.b. ohlrogge [1991] j biol chem 266: 1858-1865), the in vivo acyl-acyl carrier protein (acp) pools were measured in spinach (spinacia oleracea) leaves and changes in their levels were compared to changes in the rates of fatty acid biosynthesis. to further examine the pools of substrates and cofactors for fatty acid biosynthesis and to evaluate metabolic regulation of this pathway, we have now examined the coenzyme a (coa) and short chain a ... | 1992 | 16653077 |
| isolation of a putative carboxysomal carbonic anhydrase gene from the cyanobacterium synechococcus pcc7942. | the type ii mutants of the cyanobacterium synechococcus pcc7942 (g.d. price, m.r. badger [1989] plant physiol 91: 514-525) are able to accumulate a large pool of inorganic carbon inside the cell, but are unable to utilize it for co(2) fixation, resulting in a high co(2)-requiring phenotype. we have isolated a 3.5-kb bamhi clone (pt2) that complements the type ii mutants, and complementation analysis with dna subclones indicated that the complementing region was located in the 0.75-kb xhoi-bg/ii ... | 1992 | 16653060 |
| comparative studies of the light modulation of nitrate reductase and sucrose-phosphate synthase activities in spinach leaves. | we recently obtained evidence that the activity of spinach (spinacia oleracea l.) leaf nitrate reductase (nr) responds rapidly and reversibly to light/dark transitions by a mechanism that is strongly correlated with protein phosphorylation. phosphorylation of the nr protein appears to increase sensitivity to mg(2+) inhibition, without affecting activity in the absence of mg(2+). in the present study, we have compared the light/dark modulation of sucrose-phosphate synthase (sps), also known to be ... | 1992 | 16653049 |
| sucrose phosphate synthase and sucrose accumulation at low temperature. | the influence of growth temperature on the free sugar and sucrose phosphate synthase content and activity of spinach (spinacia oleracea) leaf tissue was studied. when plants were grown at 25 degrees c for 3 weeks and then transferred to a constant 5 degrees c, sucrose, glucose, and fructose accumulated to high levels during a 14-d period. predawn sugar levels increased from 14- to 20-fold over the levels present at the outset of the low-temperature treatment. sucrose was the most abundant free s ... | 1992 | 16652990 |
| plant dihydroxyacetone phosphate reductases : purification, characterization, and localization. | a cytosolic form of dihydroxyacetone phosphate (dhap) reductase was purified 200,000-fold from spinach (spinacia oleracea l.) leaves to apparent electrophoretic homogeneity. the purification procedure included anion-exchange chromatography, gel filtration, hydrophobic chromatography, and dye-ligand chromatography on green-a and red-a agaroses. the enzyme, prepared in an overall yield of 14%, had a final specific activity of about 500 mumol of dhap reduced min(-1) mg(-1) protein, a subunit molecu ... | 1992 | 16652968 |
| characterization of an electron transport pathway associated with glucose and fructose respiration in the intact chloroplasts of chlamydomonas reinhardtii and spinach. | the role of an electron transport pathway associated with aerobic carbohydrate degradation in isolated, intact chloroplasts was evaluated. this was accomplished by monitoring the evolution of (14)co(2) from darkened spinach (spinacia oleracea) and chlamydomonas reinhardtii chloroplasts externally supplied with [(14)c]fructose and [(14)c]glucose, respectively, in the presence of nitrite, oxaloacetate, and conventional electron transport inhibitors. addition of nitrite or oxaloacetate increased th ... | 1992 | 16652964 |
| effects of the air pollutant so(2) on leaves : inhibition of sulfite oxidation in the apoplast by ascorbate and of apoplastic peroxidase by sulfite. | after so(2) has entered leaves of spinach (spinacia oleracea) through open stomata and been hydrated in the aqueous phase of cell walls, the sulfite formed can be oxidized to sulfate by an apoplastic peroxidase that is normally involved in phenol oxidation. the oxidation of sulfite is competitive with the oxidation of phenolics. during sulfite oxidation, the peroxidase is inhibited. in the absence of ascorbate, which is a normal constituent of the aqueous phase of the apoplast, peroxidative sulf ... | 1992 | 16652957 |
| characterization of a new stearoyl-acyl carrier protein desaturase gene from jatropha curcas. | a new full-length cdna of stearoyl-acyl carrier protein desaturase was obtained by rt-pcr and race techniques from developing seeds of jatropha curcas. sequence alignment showed that its deduced amino acid sequence had high similarity with other stearoyl-acyl carrier protein desaturases. the gene was functionally expressed in e. coli and the desaturating activity of recombinant protein was easily detected when assayed in vitro with added spinach ferredoxin. southern blot analysis indicated that ... | 2006 | 16642305 |
| soil arsenic availability and the transfer of soil arsenic to crops in suburban areas in fujian province, southeast china. | the bioavailability, soil-to-plant transfer and associated health risks of arsenic in soils collected from paddy rice fields and vegetable fields in suburban areas of some major cities of fujian province were investigated. the total soil concentrations of arsenic ranged from 1.29 to 25.28 mg kg(-)(1) with a mean of 6.09 mg kg(-)(1). available (nah(2)po(4)-extractable) arsenic content accounted for 0.7-38.2% of total soil arsenic and was significantly correlated with total soil arsenic content. f ... | 2006 | 16624379 |
| glycerate-oxidizing activity of glycolate oxidase from leaves of spinacia oleracea. | glycolate oxidase (go) was purified to homogeneity from leaves of spinach (spinacia oleracea). through detecting the consumption of oxygen and the formation of hydrogen peroxide in the assay solution, it was found that go could also oxidize glycerate, another metabolite in the photorespiratory pathway, and use fmn and fad, but not riboflavin and lumiflavin, as its cofactors. the optimum reaction ph, km for glycerate, k(cat) and activation energy of this oxidizing reaction were determined to be 8 ... | 2006 | 16622317 |
| polycations globally enhance binding of 14-3-3omega to target proteins in spinach leaves. | the binding of 14-3-3omega to phosphorylated nitrate reductase (pnr) is stimulated by cations such as mg(2+) or spermine, and decreased by 5'-amp. in order to determine whether binding to other cellular proteins is affected similarly, far-western overlays of extracts prepared from light- or dark-treated spinach (spinacia oleracea) leaves were performed using digoxigenin (dig)-labeled arabidopsis 14-3-3omega. when separated by sds-page, approximately 25 proteins of >35 kda could be resolved that ... | 2006 | 16621845 |
| binding of 16s rrna to chloroplast 30s ribosomal proteins blotted on nitrocellulose. | protein-rna associations were studied by a method using proteins blotted on a nitrocellulose sheet. this method was assayed with escherichia coli 30s ribosomal components. in stringent conditions (300 mm nacl or 20 degrees c) only 9 e. coli ribosomal proteins strongly bound to the 16s rrna: s4, s5, s7, s9, s12, s13, s14, s19, s20. 8 of these proteins have been previously found to bind independently to the 16s rrna. the same method was applied to determine protein-rna interactions in spinach chlo ... | 1984 | 16617474 |
| growth-promoting effect on iron-sulfur proteins on axenic cultures of entamoeba dispar. | a growth-promoting factor (gpf) that promotes the growth of entamoeba dispar under axenic culture conditions was found in fractions of mitochondria (mt), hydrogenosomes (hg) and chloroplasts (cp) obtained from cells of six different protozoan, mammalian and plant species. we were able to extract the gpf from the cp-rich leaf cells of a plant (spiderwort: commelina communis l.) in an acetone-soluble fraction as a complex of chlorophyll with low molecular weight proteins (molecular weight [mw] app ... | 2006 | 16605067 |
| oxalate-containing phytocomplexes as dentine desensitisers: an in vitro study. | it is known that pulpal fluid movement through dentinal tubules causes dentinal hypersensitivity and that pain can be reduced by decreasing the fluid flow. the aim of this study was to evaluate dentinal permeability and morphology after a single exposure to experimental phytocomplex substances containing oxalates. the treatments tested were experimental pastes, gels and solutions of phytocomplexes (extracted from rhubarb, spinach and mint), an experimental paste containing 5% potassium oxalate, ... | 2006 | 16603120 |
| mechanisms for light-dependent regulation of ribulose-1,5-bisphosphate carboxylase activity and photosynthesis in intact leaves. | the mechanisms involved in the in vivo light-dependent regulation of ribulose-1,5-bisphosphate (rbup(2)) carboxylase [3-phospho-d-glycerate carboxy-lyase (dimerizing), ec 4.1.1.39] activity in intact leaves were studied. in the three species examined, phaseolus vulgaris, beta vulgaris, and spinacea oleracea, the regulated level of rbup(2) carboxylase activity (assayed in vitro with saturating substrate) was highly correlated (r = 0.96) with the rate of net co(2) uptake of the corresponding leave ... | 1988 | 16593934 |
| betaine synthesis in chenopods: localization in chloroplasts. | plants from several families (chenopodiaceae, gramineae, compositae) accumulate betaine (glycine betaine) in response to salt or water stress via the pathway: choline --> betainal (betaine aldehyde) --> betaine. betaine accumulation is probably a metabolic adaptation to stress. intact protoplasts from leaves of spinach (spinacia oleracea) oxidized [(14)c]choline to betainal and betaine, as did protoplast lysates. upon differential centrifugation, the [(14)c]choline-oxidizing activity of lysates ... | 1985 | 16593569 |
| nmr study of chloride ion interactions with thylakoid membranes. | the role of cl(-) in photosynthetic o(2) evolution has been investigated by observing the (35)cl nmr linewidth under a variety of conditions in aqueous suspensions of chloroplasts, primarily for the halophytes avicennia germinans, avicennia marina, and aster tripolium but also for spinach. the line broadening shows there is weak, ionic binding of cl(-) to thylakoids, the bound cl(-) exchanging rapidly (>>10(4) sec(-1)) with free cl(-) in solution. the binding is necessary for o(2) evolution to o ... | 1984 | 16593474 |
| effects of cu deficiency on photosynthetic electron transport. | the role of copper (cu) in photosynthetic electron transport was explored by using cu deficiency in sugar beet as an experimental approach. copper influenced electron transport at two sites in addition to plastocyanin. under mild deficiency (0.84 nmol of cu per cm(2) of leaf area), electron transport between the two photosystems (ps) is inhibited but not electron transport within ps i or ps ii measured separately. the chlorophyll/plastoquinone ratio was normal in cu-deficient plants. however, th ... | 1984 | 16593455 |
| extensive and widespread homologies between mitochondrial dna and chloroplast dna in plants. | we used hybridization techniques to demonstrate that numerous sequence homologies exist between cloned mung bean and spinach chloroplast dna (ctdna) restriction fragments and mtdnas from corn, mung bean, spinach, and pea. the strongest cross-homologies are between clones derived from the ctdna inverted repeat and mtdna from corn and pea, although all the ctdna clones tested hybridized to at least one mtdna restriction fragment. known chloroplast genes showing strong mtdna homologies include thos ... | 1984 | 16593442 |
| primary structure of the m subunit of the reaction center from rhodopseudomonas sphaeroides. | the reaction center is a membrane-bound bacteriochlorophyll-protein complex that mediates the primary photochemical events in the photosynthetic bacterium rhodopseudomonas sphaeroides. the previously determined amino-terminal sequences of the three subunits of the reaction center protein were used to design synthetic mixed oligonucleotide probes for the structural genes encoding the subunits. one of these probes was used to isolate and clone a fragment of dna from r. sphaeroides that contained t ... | 1983 | 16593385 |
| molecular cloning and sequence analysis of the cyanobacterial gene for the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase. | ribulose-1,5-bisphosphate carboxylase/oxygenase consists of large subunits (ls) and small subunits. in plants, the ls is encoded in chloroplast dna and the small subunit, in nuclear dna. in cyanobacteria, both subunits are thought to be encoded in chromosomal dna because of prokaryotes. the gene for the ls of ribulose-1,5-bisphosphate carboxylase/oxygenase from a cyanobacterium, anacystis nidulans 6301, has been cloned in pbr322 and subjected to sequence analysis. the coding region contains 1,41 ... | 1983 | 16593333 |
| isolation and sequence of the gene for the large subunit of ribulose-1,5-bisphosphate carboxylase from the cyanobacterium anabaena 7120. | cloned dna probes containing genes coding for the large subunit of ribulose-1,5-bisphosphate carboxylase (rbca) of corn and of chlamydomonas were used to identify, by heterologous hybridization, dna fragments from anabaena 7120 carrying the corresponding gene sequence. the same probes were used to isolate, from a recombinant lambda library, a 17-kilobase-pair ecori anabaena dna fragment containing the coding sequence for the rbca gene. the entire coding sequence, as well as 210 base pairs of 5' ... | 1983 | 16593300 |
| an arabidopsis thaliana mutant defective in chloroplast dicarboxylate transport. | reactions of the photorespiratory pathway of c(3) plants are found in three subcellular organelles. transport processes are, therefore, particularly important for maintaining the uninterrupted flow of carbon through this pathway. we describe here the isolation and characterization of a photorespiratory mutant of arabidopsis thaliana defective in chloroplast dicarboxylate transport. genetic analysis indicates the defect is due to a simple, recessive, nuclear mutation. glutamine and inorganic phos ... | 1983 | 16593285 |
| nucleotide sequence of the gene for the m(r) 32,000 thylakoid membrane protein from spinacia oleracea and nicotiana debneyi predicts a totally conserved primary translation product of m(r) 38,950. | the gene for the so-called m(r) 32,000 rapidly labeled photosystem ii thylakoid membrane protein (here designated psba) of spinach (spinacia oleracea) chloroplasts is located on the chloroplast dna in the large single-copy region immediately adjacent to one of the inverted repeat sequences. in this paper we show that the size of the mrna for this protein is approximately 1.25 kilobases and that the direction of transcription is towards the inverted repeat unit. the nucleotide sequence of the gen ... | 1982 | 16593262 |
| purification, primary structure, and homology relationships of a chloroplast ribosomal protein. | a chloroplast ribosomal protein that showed immunological homology to escherichia coli ribosomal protein l12 was purified from spinach (spinacia oleracea) leaves and its primary structure was determined by manual micro edman degradation. the protein is composed of 130 amino acid residues and has m(r) 13,576. it shows structural features characteristic of the l12 proteins of eubacterial 70s ribosomes (e.g., identical amino acid residues in about 50% of the sequence) but no apparent homology to th ... | 1982 | 16593249 |
| structures of the genes for the beta and epsilon subunits of spinach chloroplast atpase indicate a dicistronic mrna and an overlapping translation stop/start signal. | a 2,4-kilobase-pair region of spinach chloroplast dna adjacent to the gene for the large subunit of ribulosebisphosphate carboxylase has been analyzed by rna hybridization, in vitro transcription/translation, and dna sequence determination. the analysis indicates that this region carries the genes for the beta and epsilon subunits of chloroplast atpase and that the two genes are cotranscribed into a dicistronic mrna with 4-base-pair overlap between the stop codon of the beta-subunit gene and the ... | 1982 | 16593238 |
| immunological similarity between a cyanobacterial enzyme and a nuclear dna-encoded plastid-specific isozyme from spinach. | the immunochemical properties of the plastid and cytosolic isozymes of phosphoglucose isomerase (glucosephosphate isomerase; d-glucose-6-phosphate ketol-isomerase, ec 5.3.1.9) in spinach (spinacia oleracea) and the single phosphoglucose isomerase enzyme from the cyanobacterium synechococcus sp. were compared by an application of the enzyme-linked immunosorbent assay. utilizing antibodies made in rabbits against subunits of purified plastid and cytosolic phosphoglucose isomerase isozymes from spi ... | 1982 | 16593236 |
| cloning, mapping, and in vitro transcription-translation of the gene for the large subunit of ribulose-1,5-bisphosphate carboxylase from spinach chloroplasts. | an 11.2-kilobase pair (kbp) bamhi restriction nuclease fragment from spinach chloroplast dna has been found to contain the gene for the large subunit (ls) of ribulose-1,5-bisphosphate carboxylase [rup(2) carboxylase; 3-phospho-d-glycerate carboxy-lyase (dimerizing), ec 4.1.1.39]. the gene was located by hybridization of cloned chloroplast dna fragments containing the maize ls gene (bedbrook, j. r., coen, d. m., beaton, a. r., bogorad, l. & rich, a. (1979) j. biol. chem. 254, 905-910) to spinach ... | 1981 | 16593031 |
| isolation and characterization of calmodulin from spinach leaves and in vitro translation mixtures. | calmodulin, a multifunctional calcium-modulated protein, has been isolated from spinach leaf tissue and from spinach leaf messenger rna translation products. the translation protein and the spinach leaf protein have been partially characterized and compared to vertebrate calmodulins. spinach leaf calmodulin will quantitatively activate bovine brain phosphodiesterase and will undergo a calcium-dependent shift in electrophoretic mobility similar to that of bovine brain calmodulin. in the presence ... | 1980 | 16592801 |
| biosynthesis and assembly of the proton-translocating adenosine triphosphatase complex from chloroplasts. | the h(+)-translocating atpase complex of chloroplasts consists of at least eight nonidentical subunits. five of these (alpha, beta, gamma, delta, and epsilon subunits) collectively constitute the globular extramembranous cf(1) portion of the complex. the remaining three subunits (i-iii) represent the membrane-embedded portion. biosynthesis and assembly of these subunits were studied by pulse-labeling isolated spinach chloroplasts in the presence of cycloheximide or chloramphenicol and by transla ... | 1980 | 16592786 |
| hydrogen evolution by a chloroplast-ferredoxin-hydrogenase system. | spinach chloroplast preparations were mixed with clostridium kluyveri hydrogenase and ferredoxin. hydrogen evolution could be measured in the light in the absence of any added electron donors. inhibition of the water-splitting reaction or of photosystem ii reduced the amount of h(2) evolved more than 95%, indicating that h(2)o was the electron donor in this reaction. the rates of h(2) evolution observed were up to 20% of those measured in the presence of an oxygen-consuming reaction or of photos ... | 1973 | 16592104 |
| partially purified photosynthetic reaction centers from plant tissues. | the prior removal of carotenoids from photosynthetic membranes of plants by means of organic extraction allows triton x-100 to remove and solubilize small particles that are greatly enriched in reaction center chl, p700. four plant species have been examined: spinach, bush bean (phaseolus vulgaris), the blue-green alga anabaena variabilis, and euglena. the particles obtained are generally similar and have a ratio of one p700 to approximately 30 chlorophylls (in spinach the ratio is 1 to 28). exp ... | 1969 | 16591778 |
| epr in chromatophores from rhodospirillum rubrum and in quantasomes from spinach chloroplasts. | 1962 | 16590952 | |
| nucleotide sequence of a multiple-copy gene for the b protein of photosystem ii of a cyanobacterium. | chloroplast photogene 32 codes for the 32-kilodalton triazine herbicide-binding protein at the b site of electron transport in photosystem ii of the photosynthetic apparatus-its product is the b protein and the gene is accordingly designated ps2b here. the cyanobacteria anacystis nidulans r2, fremyella diplosiphon, and nostoc sp. mac each contain several copies of ps2b. the sequence of one copy of ps2b from fremyella, ps2b-1, has been determined. the longest open reading frame would code for a p ... | 1984 | 16578775 |
| procedure for rapid isolation of photosynthetic reaction centers using cytochrome c affinity chromatography. | horse heart cytochrome c linked to sepharose 4b is used to purify reaction centers from rhodopseudomonas sphaeroides r-26. this procedure allows for an initial recovery of 80-90% of the bacterial reaction centers present in chromatophore membranes. high purity reaction centers (a(280)/a(802) < 1.30) can be obtained with a 30% recovery. reaction centers from wild-type rps. sphaeroides and rps. capsulata also bind to a cytochrome c column. cytochrome c affinity chromatography can also be used to i ... | 1983 | 16578765 |
| evidence that cytochrome b559 is involved in superoxide production in photosystem ii: effect of synthetic short-chain plastoquinones in a cytochrome b559 tobacco mutant. | light-induced production of superoxide (o2*-) in spinach psii (photosystem ii) membrane particles was studied using epr spin-trapping spectroscopy. the presence of exogenous pqs (plastoquinones) with a different side-chain length (pq-n, n isoprenoid units in the side-chain) enhanced o2*- production in the following order: pq-1>pq-2>>pq-9. in psii membrane particles isolated from the tobacco cyt (cytochrome) b559 mutant which carries a single-point mutation in the beta-subunit and also has a decr ... | 2006 | 16569212 |