| the magnetic susceptibility of oxidized and reduced ferredoxins from spinach and parsley and the high potential protein from chromatium. | | 1969 | 5783833 |
| uptake of isolated chloroplasts by mammalian cells. | mouse fibroblasts (l cells) in suspension culture incorporated isolated chloroplasts of spinach and african violets and isolated mitochondria of chicken liver. the organelles resided in the cell cytoplasm and were not contained in vacuoles or digestion vesicles. green cells divided like normal cells. green chloroplasts were followed for five cell generations or 5 days, at which time hybrid cells were greatly outnumbered by nongreen progeny cells. the ingested chloroplasts retained their structur ... | 1969 | 5801593 |
| adp-d-glucose:alpha-1,4-glucan alpha-4-glucosyltransferase of spinach leaves. enzymatic synthesis of amylopectin-type polysaccharide in a two-enzyme system. | | 1969 | 5821017 |
| methyl viologen-linked sulfite reductase from spinach leaves. | | 1969 | 5824566 |
| [about the reason of enrichment of spinach (spinacia oleracea l.) with nitrate and nitrite in relation to methemogloginemia in rats]. | | 1965 | 5843815 |
| choline kinase and phosphorylcholine phosphatase in plants. | choline kinase was present in barley and wheat roots and leaves of barley, wheat, tobacco, spinach and squash plants. the kinase was purified 25-fold from spinach leaves. the enzyme had a broad ph optimum between 7.5 and 10.0. mg(++) was required for activity and in the presence of mg(++) the enzyme was relatively stable. maximum enzyme activity was obtained when the mg(++): atp ratio was 1:1. the k(m) was 1 x 10(-4)m. the kinase from leaves was similar to that from rapeseed or from yeast, excep ... | 1966 | 5908634 |
| effect of cycocel derivatives and gibberellin on choline kinase and choline metabolism. | cycocel stimulated the activity of partial purified choline kinase from spinach or squash leaves, but it inhibited the activity of yeast choline kinase. the activity of different cycocel analogs on plant growth corresponded to their stimulatory effect on the isolated choline kinase. cycocel had no effect upon the activity of a plant phosphatase which hydrolyzed phosphorylcholine nor upon adenosine triphosphatase from wheat roots or leaves. gibberellin a(3) inhibited choline kinase activity and r ... | 1966 | 5908635 |
| comment on a recent model of the iron complex in spinach ferredoxin. | | 1966 | 5970521 |
| a factor from spinach leaves interacting with chlorophylls. | | 1967 | 6048856 |
| thermodynamics of light emission and free-energy storage in photosynthesis. | a planck law relationship between absorption and emission spectra is used to compute the fluorescence spectra of some photosynthetic systems from their absorption spectra. calculated luminescence spectra of purple bacteria agree well but not perfectly with published experimental spectra. application of the planck law relation to published activation spectra for systems i and ii of spinach chloroplasts permits independent calculation of the luminescence spectra of the two systems; if the luminesc ... | 1967 | 6048879 |
| absorption of phytol from dietary chlorophyll in the rat. | the fate of ingested chlorophyll-particularly of the phytol portion of the molecule-was studied. uniformly (14)c-labeled pheophytin a (the mg-free derivative of chlorophyll a) was prepared from an extract of tobacco leaves grown in (14)co(2), and was administered by stomach tube to rats in which the thoracic duct had been cannulated. only about 2% of the administered radioactivity was absorbed in 24 hr, largely into the thoracic duct lymph. moreover, only a fraction of this lymph radioactivity w ... | 1967 | 6057491 |
| junctions of the large single copy region and the inverted repeats in spinacia oleracea and nicotiana debneyi chloroplast dna: sequence of the genes for trnahis and the ribosomal proteins s19 and l2. | this work describes the organization, at the nucleotide sequence level, of genes flanking the junctions of the large single copy regions and the inverted repeats of spinacia oleracea (spinach) and nicotiana debneyi chloroplast dnas. in both genomes, trnh1, the gene for trna-his(gug) is located at the extremity of the large single copy region 3' to psba, the gene for the 35 kd photosystem 2 protein. both psba and trnh1 are transcribed towards the inverted repeat. in spinach, the first 48 codons o ... | 1984 | 6089120 |
| isolation and characterization of thioredoxin f from the filamentous cyanobacterium, anabaena sp. 7119. | two thioredoxin fractions had previously been reported to occur in anabaena 7119 by buchanan and co-workers (yee, b. c., dela torre, a., crawford, n. a., lara, c., carlson, d. e., and buchanan, b. b. (1981) arch. microbiol. 130, 14-18). these proteins were detected by their ability to activate spinach fructose-1,6-bisphosphatase (fru-p2-ase). the partially purified proteins resembled similar thioredoxins found in spinach chloroplasts and were designated thioredoxin f (tf) for the fraction most e ... | 1984 | 6094540 |
| structure of the spinach chloroplast genes for the d2 and 44 kd reaction-centre proteins of photosystem ii and for trnaser (uga). | we have determined the sequence of the spinach (spinacia oleracea) chloroplast genes for the photosystem ii proteins, d2 and the 44 kd reaction-centre, chlorophyll a-binding protein, and for trnaser (uga). the 3' end of the d2 gene overlaps the first 50 bp of the 5' end of the gene for the 44 kd protein. northern rna hybridization analysis indicates the two genes are cotranscribed into a single 3.5 kb rna. the predicted molecular weight of the 353-residue d2 protein is 39536 and that of the 473- ... | 1984 | 6096808 |
| acetyl-coenzyme a carboxylase from avocado (persea americana) plastids and spinach (spinacia oleracea) chloroplasts. | preparations of acetyl-coa carboxylase [acetyl-coa-carbon-dioxide ligase (adp-forming), ec 6.4.1.2] have been obtained from the plastids of avocado (persea americana) fruit mesocarp and from spinach (spinacia oleracea) chloroplasts. both preparations required bovine serum albumin, hco3-, citrate and glycerol for stabilization. the molecular weight of the avocado enzyme was about 6.5 x 10(5) on the basis of 1 mol of biotin/mol of enzyme, the behaviour of both enzymes on gel filtration being in ac ... | 1980 | 6146308 |
| oxetin, a new antimetabolite from an actinomycete. fermentation, isolation, structure and biological activity. | a new amino acid-antimetabolite, oxetin, was isolated from a fermentation broth of a streptomyces sp. om-2317, a soil isolate. the chemical structure was elucidated as (2r,3s)-3-amino-2-oxetane carboxylic acid by analysis of the spectral data and by x-ray diffraction methods. the antibiotic is the first natural product possessing an oxetane ring. certain microorganisms were inhibited by oxetin only when cultivated in minimal media. the inhibitory action was reversed by several amino acids such a ... | 1984 | 6150928 |
| protein synthesis in chloroplasts. viii. differential synthesis of chloroplast proteins during spinach leaf development. | excised primary leaves of spinach (spinacia oleracea) incorporate [35s]-methionine into a number of chloroplast polypeptides. the ratio of incorporation of isotope into the large subunit of ribulose bisphosphate carboxylase relative to a thylakoid polypeptide (peak d) decreases during leaf development in whole leaves; this changing pattern of incorporation is also observed in isolated chloroplasts where these two polypeptides are the major products of protein synthesis. chloroplast rna prepared ... | 1980 | 6154482 |
| purification and immunological studies of glutathione reductase from rat liver. evidence for an antigenic determinant at the nucleotide-binding domain of the enzyme. | glutathione reductase has been purified to homogeneity by a method which is an improvement of an earlier procedure (carlberg, i. and mannervik, b. (1975) j. biol. chem. 250, 5475-5480). the new steps in the purification scheme include affinity chromatography on 2',5' adp-sepharose 4b. antibodies to glutathione reductase from rat liver were raised in rabbits and used for analysis of the enzyme by quantitative 'rocket' immunoelectrophoresis. glutathione reductase from human erythrocytes, porcine e ... | 1981 | 6170346 |
| isolation, purification and characterization of the atpase complex from the thermophilic cyanobacterium synechococcus 6716. | the atpase complex is isolated and purified from membrane vesicles of the thermophilic cyanobacterium synechococcus 6716 by octyl glucoside and cholic acid by a modification of the procedure for its extraction from spinach chloroplasts. the complex is purified by differential centrifugation and ammonium sulfate precipitation and by gel filtration on sepharose 6b. the purified fraction, without any phycocyanin contamination, shows atp hydrolysis activity and pi/atp exchange activity of 1564 and 3 ... | 1983 | 6197306 |
| reconstitution of 50 s ribosomal subunits from bacillus stearothermophilus with 5 s rna from spinach chloroplasts and low-mr rna from mitochondria of locusta migratoria and bovine liver. | reconstitution experiments with 50 s ribosomal subunits from bacillus stearothermophilus demonstrate that spinach chloroplast 5 s rrna can be incorporated into the bacterial ribosome and yield biologically active particles, thereby establishing the eubacterial nature of chloroplast 5 s rrna. in contrast, mitochondria from locusta migratoria or bovine liver do not appear to contain discrete, low-mr rnas, which can replace 5 s rrna in the functional reconstitution of b. stearothermophilus ribosome ... | 1984 | 6201395 |
| inhibition by palmitoyl coa of dynein atpase from sea urchin spermatozoa. | atpase of 14s dynein, extracted from spermatozoa of the sea urchin, hemicentrotus pulcherrimus, and partially purified by sucrose density gradient centrifugation, was inhibited non-competitively by palmitoyl coa at concentrations higher than 20 microns, and was stimulated at concentrations between 2 microns and 10 microns. the effects of palmitoyl coa on dynein atpase were reversed by bovine serum albumin (1 mg/ml) and spermine (0.1 and 1 mm). myristoyl coa exerted effects similar to those of pa ... | 1982 | 6215400 |
| properties of a novel atpase enzyme in chromaffin granules. | membranes were isolated from mitochondria and chromaffin granules of bovine adrenal medullae. the cross-contamination between the two membranes was examined by comparing the radioactive bands on autoradiograms of gels after phosphorylation of the membranes with [gamma-32p]-atp and decoration with [125i]concanavalin a and [125i]protein a with antibody that was raised against chromaffin-granule membranes. it was found that the membranes cross-contaminated each other by less than 10%. the technique ... | 1982 | 6219106 |
| manganese proteins isolated from spinach thylakoid membranes and their role in o2 evolution. i. a 56 kilodalton managnese-containing protein, a probable component of the coupling factor enzyme. | the binding of endogenous manganese (mn) to proteins released from spinach grana-thylakoid membranes by 2% cholate detergent or by osmotic shock is investigated. a mixture of 15-20 proteins is released by cholate and has been separated by isoelectric focusing in a sucrose gradient or by chromatofocusing. mn coelutes with several proteins, but is lost upon dialysis. a dramatic redistribution of this mn occurs in proteins released by osmotic shock in the presence of hydrophobic and hydrophilic oxi ... | 1984 | 6234021 |
| human exposure to nickel. | in order of abundance in the earth's crust, nickel ranks as the 24th element and has been detected in different media in all parts of the biosphere. thus, humans are constantly exposed to this ubiquitous element, though in variable amounts. the average natural nickel exposure from food in the past has probably been somewhat, but not much, below current levels. nickel is a useful metal, particularly in various alloys, in batteries and in nickel-plating. nickel compounds are used especially as cat ... | 1984 | 6241927 |
| thioredoxin/fructose-1,6-bisphosphatase affinity in the enzyme activation by the ferredoxin-thioredoxin system. | in this work we analyze the affinity relationship between photosynthetic fructose-1,6-bisphosphatase and ferredoxin and thioredoxin from spinach leaves, two components of the proposed light-activation system of this enzyme, using affinity techniques on ferredoxin- and thioredoxin-sepharose columns. oxidized and reduced ferredoxin did not show enzyme affinity, whereas thioredoxin, both the oxidized and the dithiothreitol-reduced form, exhibited a strong bisphosphatase affinity at ph 7.5; this thi ... | 1981 | 6269592 |
| clone banks of the mung bean, pea and spinach chloroplast genomes. | all but one of the psti restriction fragments from mung bean, pea, and spinach chloroplast dnas have been stably cloned into pbr322. large fragments (15-54 kb) were cloned at low efficiencies which decreased with increasing fragment length. however, plasmids containing fragments above 25-30 kb were too unstable to be useful. in particular, pbr322 derivatives containing the largest mung bean and spinach fragments (34 kb and 54 kb, respectively) are extremely unstable and rapidly delete parts of t ... | 1981 | 6271631 |
| purification and properties of adenylyl sulphate:ammonia adenylyltransferase from chlorella catalysing the formation of adenosine 5' -phosphoramidate from adenosine 5' -phosphosulphate and ammonia. | extracts of chlorella pyrenoidosa, euglena gracilis var. bacillaris, spinach, barley, dictyostelium discoideum and escherichia coli form an unknown compound enzymically from adenosine 5'-phosphosulphate in the presence of ammonia. this unknown compound shares the following properties with adenosine 5'-phosphoramidate: molar proportions of constituent parts (1 adenine:1 ribose:1 phosphate:1 ammonia released at low ph), co-electrophoresis in all buffers tested including borate, formation of amp at ... | 1981 | 6274307 |
| conservation of sequence arrangement among higher plant chloroplast dnas: molecular cross hybridization among the solanaceae and between nicotiana and spinacia. | isolated, nick-translated pvu ii fragments of nicotiana tabacum chloroplast dna produce specific intra- and intergeneric hybridization signals with chloroplast dna digests from several representatives of the solanaceae. these data, along with similarities in restriction enzyme patterns, permit construction of physical maps for nicotiana line 92 (a cytoplasmic substitution line), atropa belladonna and petunia parodii. plastid-dna map differences among the solanaceae are shown to result from singl ... | 1981 | 6278451 |
| chloroplast dna rearrangements are more frequent when a large inverted repeat sequence is lost. | we examined the arrangement of sequences common to seven angiosperm chloroplast genomes. the chloroplast dnas of spinach, petunia and cucumber are essentially colinear. they share with the corn chloroplast genome a large inversion of approximately 50 kb relative to the genomes of three legumes--mung bean, pea and broad bean. there is one additional rearrangement, a second, smaller inversion within the 50 kb inversion, which is specific to the corn genome. these two changes are the only detectabl ... | 1982 | 6288261 |
| nucleotide sequences of tobacco chloroplast genes for elongator trnamet and trnaval (uac): the trnaval (uac) gene contains a long intron. | the nucleotide sequences of tobacco chloroplast genes for elongator trnamet and trnaval (uac) have been determined. the trnaval gene contains a 571 base pairs intron located in the anticodon loop. the trnaval gene is transcribed as a 750 bases precursor rna molecule. both trnas deduced from the dna sequences show 97% sequence homologies with those of spinach chloroplasts. | 1982 | 6296781 |
| the amino acid sequence of the beta-subunit of atp synthase from bovine heart mitochondria. | the amino acid sequence of the beta-subunit of bovine heart mitochondrial atp synthase has been determined by protein sequence analysis. the polypeptide chain of 478 amino acids is blocked at its nh2 terminal. comparison of this sequence with sequences of the corresponding proteins from escherichia coli (saraste, m., gay, n.j., eberle, a., runswick, m.j., and walker, j.e. (1981) nucleic acids res. 9, 5287-5296) and maize and spinach chloroplasts krebbers, e.t., larrinua, i. m., mcintosh, l., and ... | 1983 | 6298222 |
| nucleotide sequence of tobacco chloroplast gene for the alpha subunit of proton-translocating atpase. | the tobacco chloroplast gene for the alpha subunit of proton-translocating atpase has been cloned and sequenced. the coding region contains 1521 bp (507 codons). the nucleotide sequence and the deduced amino acid sequence show 55% and 54% homologies with those of the e. coli alpha subunit, respectively. the deduced amino acid composition is quite similar to that estimated for the spinach alpha subunit. | 1983 | 6300797 |
| mineral balances of human subjects consuming spinach in a low-fiber diet and in a diet containing fruits and vegetables. | the effects of spinach in the diet on mineral balances were examined in 12 men who consumed three controlled diets for 4 wk each. diet 1, a low-fiber diet, contained spinach, which is high in oxalic acid, every other day. diet 2 contained fiber in fruits and vegetables, including spinach every other day. diet 3 was the same as diet 2 except that cauliflower, which is low in oxalic acid, replaced the spinach. during wk 4, mean balances of calcium, magnesium, and zinc on diet 2 were negative and s ... | 1983 | 6305185 |
| glycerate kinase from leaves of c3 plants. | d-glycerate-3-kinase (ec 2.7.1.31) in six c3 species, including dicots (pisum sativum, spinacea oleracea, antirrhinum majus) and monocots (secale cereale, hordeum vulgare, avena sativa), ranged in activity from 44 to 353 mumol x mg chl-1 x h-1. studies with protoplast extracts of these species indicate that the enzyme is localized in the chloroplasts. glycerate kinase was partially purified from secale (rye, 288-fold) and pisum (pea, 252-fold) chloroplasts by deae-cellulose chromatography, sucro ... | 1983 | 6307152 |
| the use of a water-soluble carbodiimide to cross-link cytochrome c to plastocyanin. | a water-soluble carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, has been used to cross-link horse heart cytochrome c to spinach chloroplast plastocyanin. the complex was formed in yields up to 90% and was found to have a stoichiometry of 1 mol plastocyanin per mol cytochrome c. the cytochrome c in the complex was fully reducible by ascorbate and potassium ferrocyanide, and had a redox potential only 25 mv less than that of native cytochrome c. the complex was nearly completely inact ... | 1983 | 6307354 |
| the nucleotide sequence for the large subunit of ribulose 1,5-bisphosphate carboxylase from a unicellular cyanobacterium, synechococcus pcc6301. | the gene for the large subunit (lsu) of ribulose 1,5-bisphosphate carboxylase from a unicellular cyanobacterium, synechococcus pcc6301, was cloned using the spinach lsu gene as a hybridization probe. the coding region of the synechococcus lsu gene consists of 1419 nucleotides and shows 70% homology to the spinach nucleotide sequence. the derived amino acid sequence (472 amino acids) shows 81% homology to the spinach lsu and 78% to the maize lsu. regions containing active-site residues are highly ... | 1983 | 6307620 |
| influence of fish on the bioavailability of plant iron in the anemic rat. | the effect of fish protein and fish oil on the utilization of endogenous iron in wheat bran, spinach and soy protein isolate was investigated by using the anemic rat as an animal model. marine products were substituted for casein and corn oil in the diets of these animals. hemoglobin regeneration was one criteria used to measure iron uptake. relative biological values (rbv) were computed from a regression equation obtained from control animals receiving graded levels of feso4 x 7h2o. the rbv of ... | 1983 | 6308194 |
| studies by electron-paramagnetic-resonance spectroscopy of the molybdenum centre of spinach (spinacia oleracea) nitrate reductase. | the molybdenum centre of spinach (spinacia oleracea) nitrate reductase has been investigated by e.p.r. spectroscopy of molybdenum(v) in reduced forms of the enzyme. the resting enzyme gives no signals attributable to mo(v). however, on reduction with nadh, mo(v) signals appeared at relatively short reaction times but decreased again on prolonged exposure to excess of the substrate as the enzyme was further reduced. on brief treatment of such samples with nitrate, mo(v) signals reappeared but dis ... | 1983 | 6311159 |
| extra proton translocation and membrane potential generation--universal properties of cytochrome bc1/b6f complexes reconstituted into liposomes. | isolated cytochrome complexes from different sources like beef heart mitochondria, spinach chloroplasts, cyanobacteria, and photosynthetic bacteria were incorporated into liposomes by sonication as revealed by sucrose density gradient centrifugation and electron microscopy. the reconstituted cytochrome complexes show suppressed rates of quinol-cytochrome c/plastocyanin oxidoreduction which can be stimulated by ionophores and uncouplers. in addition, extra proton translocation out of the vesicles ... | 1983 | 6312896 |
| on the reduction of aliphatic and aromatic nitro compounds by clostridia, the role of ferredoxin and its stabilization. | crude extracts of a variety of clostridium species reduce aromatic and aliphatic nitro compounds in the presence of hydrogen gas. using different clostridia, the uptake of hydrogen by p-nitrobenzoate is about 5--10 times faster than by 2-nitroethanol. structurally rather different aliphatic nitro compounds show rates which differ by less than a factor of 3. hydrogenase from clostridium kluyveri and ferredoxins from clostridium spec. la 1 and spinach have been purified. the combinations of the hy ... | 1983 | 6313511 |
| effect of dietary fiber on a guinea pig intestinal anaerobe, bacteroides ovatus. | the purpose of this study was to determine the effect of fibrous plant components on the growth of intestinal bacteria. an anaerobe was isolated from the guinea pig cecum and identified as bacteroides ovatus. the organism was grown anaerobically in two types of media and shown to require hemin or protoporphyrin ix. treatment of the media with water-insoluble fractions of alfalfa, cabbage, spinach or wheat bran inhibited growth of the culture. inhibition occurred whether the residue remained in t ... | 1984 | 6319647 |
| cadmium - a complex environmental problem. part ii. cadmium in sludges used as fertilizer. | in intensively populated countries efficient sewage treatment is essential to protect river quality. an inevitable by-product is sewage sludge which has to be disposed of safely and economically. utilisation of sludge as a fertilizer of agricultural land is the most economic disposal route for inland sewage-treatment works and also benefits farmers by providing a cheap manure. much of the cadmium in wastewater is concentrated into sludge which consequently contains higher concentrations of cadmi ... | 1984 | 6321225 |
| ophiobolin a. a natural product inhibitor of calmodulin. | ophiobolin a, a fungal metabolite and a phytotoxin which can stimulate the net leakage of electrolytes and glucose from maize seedling roots (tipton, c. l., paulsen, p. v., and betts, r. e. (1977) plant physiol. 59, 907-910) was found to be a potent inhibitor of calmodulin-activated cyclic nucleotide phosphodiesterase. the physiologically less active analogue, 3-anhydro-ophiobolin a, was found to be less inhibitory than ophiobolin a in the phosphodiesterase assay. the direct interaction between ... | 1984 | 6321479 |
| relationship of components in wheat bran and spinach to iron bioavailability in the anemic rat. | components found in wheat bran and spinach were evaluated as to their affect on the bioavailability of ferrous iron (i.e., feso4) by using the criteria of hemoglobin regeneration in anemic rats. the relative biological value (rbv) of iron in wheat bran and spinach (feso4 = 100%) were determined to be 124 and 53%, respectively. control diets with graded levels of feso4 did not contain dietary fiber (i.e., cellulose). adding cellulose (1.74%) or phytic acid (0.66%) at levels contained in the wheat ... | 1984 | 6321704 |
| sequence homology and structural similarity between cytochrome b of mitochondrial complex iii and the chloroplast b6-f complex: position of the cytochrome b hemes in the membrane. | the amino acid sequences of cytochrome b of complex iii from five different mitochondrial sources (human, bovine, mouse, yeast, and aspergillus nidulans) and the chloroplast cytochrome b6 from spinach show a high degree of homology. calculation of the distribution of hydrophobic residues with a "hydropathy" function that is conserved in this family of proteins implies that the membrane-folding pattern of the 42-kilodalton (kda) mitochondrial cytochromes involves 8-9 membrane-spanning domains. th ... | 1984 | 6322162 |
| [behavior of benzo(a)pyrene in the soil and passage from soil to crops]. | the behaviour of benzo[a]pyren (bap) in the soil and its passage from the soil into the crops has been investigated by means of model tests. in situ fluorescence spectroscopy enables a detection of 0.01 micrograms/bap/kg with recoveries ranged from 75 to 99.6% and an average variation coefficient of 15%. a decomposition of bap in test soils within 18 months from 30 mg/kg to 1.5 mg/kg could be attributed to decomposition by soil bacteria. after addition of bactericidal substances to the soil ther ... | 1983 | 6322471 |
| isolation and characterization of calmodulin from the motile green alga chlamydomonas reinhardtii. | calmodulin, a calcium-binding protein with no known enzymatic activity but multiple, in vitro effector activities, has been purified to apparent homogeneity from the unicellular green alga chlamydomonas reinhardtii and compared to calmodulin from vertebrates and higher plants. chlamydomonas calmodulin was characterized in terms of electrophoretic mobility, amino acid composition, limited amino acid sequence analysis, immunoreactivity, and phosphodiesterase activation. chlamydomonas calmodulin ha ... | 1984 | 6322690 |
| anion and divalent cation activation of phosphoglycolate phosphatase from leaves. | phosphoglycolate (p-glycolate) phosphatase was purified 223-fold from spinach leaves by (nh4)2so4 fractionation, deae-cellulose chromatography, and sephadex g-200 chromatography. the partially purified enzyme had a broad ph optimum between 5.6 and 8.0 and was specific for the hydrolysis of p-glycolate with a km (p-glycolate) of 26 microm. the enzyme was activated by divalent cations including mg2+, co2+, mn2+, and zn2+, and by anions including cl-, br-, no-3, and hcoo-. neither anions nor divale ... | 1984 | 6322692 |
| sequence of the genes for trnacys and trnaasp from spinach chloroplasts. | we have determined the map location and primary structure of two fragments of spinach chloroplast dna which encompass the genes for trnacysgca and trnaaspguc. identification of the genes for these two rna species is based on the sequence of their anticodon triplets and on a comparison of the sequences with those of the equivalent trnas from escherichia coli. each gene occurs only once on the spinach chloroplast genome and neither contains an intervening sequence. hybridization of the restriction ... | 1983 | 6324088 |
| a new epr signal associated with photosystem 1 of algal and plant photosynthesis. | a new low temperature electron paramagnetic resonance (epr) signal with a g-value of 1.97 was found in photosystem-1 particles from a blue-green alga, anacystis nidulans, illuminated at room temperature. a similar signal was also found in spinach photosystem-1 particles treated with thiophenol to decrease interference from a signal due to center a. in the dark, the signal appeared only when the anacystis particles were at redox potentials lower than -0.5 volts where centers a and b were also red ... | 1984 | 6327659 |
| distinct reduction of nitrofurans and metronidazole to free radical metabolites by tritrichomonas foetus hydrogenosomal and cytosolic enzymes. | anaerobic tritrichomonas foetus hydrogenosomes supplemented with pyruvate and coa effectively reduce nitrofurans and metronidazole to their respective anion free radicals. addition of purified ferredoxins from clostridium pasteurianum or spinacia oleracea to these preparations causes a great stimulation of metronidazole reduction, but does not affect nitrofuran reduction. a similar stimulatory effect of ferredoxin on metronidazole reduction, but not on nitrofuran reduction, is observed in incuba ... | 1984 | 6330106 |
| comparative structural analysis of cytoplasmic and chloroplastic 5s rrna from spinach. | 5s rrnas from spinacea oleracea cytoplasmic and chloroplastic ribosomes have been subjected to digestion with the single strand specific nuclease s1 and to chemical modification of cytidines by sodium bisulphite in order to probe the rna structure. according to these data, cytoplasmic 5s rrna can be folded as proposed in the general eukaryotic 5s rrna structure (1) and 5s rrna from chloroplastides is shown to be more related to the general eubacterial structure (2). | 1983 | 6340063 |
| a new biosynthetic route of porphyrin precursors in common between animals and plants. | an additional enzyme, 4-oxo-5-hydroxyvalerate (ohv) dehydrogenase was identified and characterized. this enzyme catalyzes the conversion of ohv to 4,5-dioxovalerate, a direct precursor of 5-aminolevulinate. the enzyme was partially purified from rat liver supernatant as two isoenzyme (ca. 40,000 and 70,000 dalton). 5-aminolevulinate was formed from ohv via 4,5-dioxovalerate by this dehydrogenase and alanine-4,5-dioxovalerate aminotransferase (ec 2.6.1.43). this dehydrogenase required nadp or nad ... | 1983 | 6342621 |
| spinach chloroplast thioredoxins in evolutionary drift. | the amino acid sequences surrounding the active sites of spinach chloroplast thioredoxins m and f have been determined. both types of thioredoxins share common ancestor genes with the e. coli one, demonstrated by invariant active site sequences. the m-type thioredoxins have closer homology with the e. coli one in the sequence analyzed as well as in enzymatic specificity, whereas the f-type is less homologous both in sequence and specificity. it suggests that the m-type gene represents a prototyp ... | 1983 | 6351859 |
| influence of photoperiod, nutrition and water availability on reproduction of male california voles (microtus californicus). | male california voles were maintained in long (14l:10d) or short photoperiods (10l:14d) for 10 weeks and fed a standard diet of rabbit chow and water ad libitum. one additional group in each photoperiod received the standard diet plus supplements of spinach 3 times weekly. a fifth group was housed in 14l:10d and fed the standard diet, but for 10 weeks water availability was restricted to several hours each morning. testes and seminal vesicles were heaviest in long-day voles fed spinach supplemen ... | 1983 | 6355461 |
| properties of a thioredoxin purified from rabbit bone marrow which fails to serve as a hydrogen donor for the homologous ribonucleotide reductase. | a thioredoxin has been highly purified from rabbit bone marrow. this thioredoxin is heat-stable, has a molecular weight of approximately 13,000, and contains 4 half-cystines. it is a substrate for the nadph-dependent thioredoxin reductase of rabbit bone marrow, catalyzes the reduction of insulin disulfides by dithiothreitol, and is a hydrogen donor for methionine sulfoxide reductase of yeast. although active as a hydrogen donor for ribonucleotide reductase of lactobacillus leichmannii, this acti ... | 1983 | 6358204 |
| comparison of ribosomal proteins of chloroplast from spinach and of e. coli. | a comparison of ribosomal proteins from escherichia coli and from chloroplasts of spinach was made using two separate methods: electrophoretic migration and immunochemical cross-reaction between blotted e. coli ribosomal proteins and chloroplast ribosomal subunits antisera. it is shown that l2 from e. coli (e-l2) and l4 from chloroplasts (cs-l4) comigrated and that e-l2 immunologically cross-reacted with the isolated cs-l4 antibody. co-migration was observed for three additional couples of 50s r ... | 1984 | 6361495 |
| acylation of plant acyl carrier proteins by acyl-acyl carrier protein synthetase from escherichia coli. | the acyl-acyl carrier protein synthetase from escherichia coli has been examined for its ability to specifically acylate acyl carrier protein (acp) from higher plants in order to develop an assay for plant acp, and to prepare labeled acyl-acp of plant origin. it was found that the e. coli enzyme was able to acylate acp from spinach, soybean, avocado, corn, and several other plants. the acylation was very specific because, in crude extracts of spinach leaves where acp represented approximately 0. ... | 1984 | 6370139 |
| a novel, general radioimmunoassay for acyl carrier proteins. | a radioimmunoassay (ria) for acyl carrier proteins (acp) is described that is based on the competitive binding between [3h]acyl-acp and unlabeled acp of the same species. the radiolabeled antigen, [3h]palmitoyl-acp, is enzymatically synthesized by escherichia coli acyl-acp synthetase. because acyl-acp synthetase can specifically radiolabel acp in crude extracts from several plant sources, the use of this enzyme to prepare [3h]acyl-acp obviates the need for pure preparations of each acp. preparat ... | 1984 | 6372545 |
| thioredoxin system of the photosynthetic anaerobe chromatium vinosum. | chromatium vinosum, an anaerobic photosynthetic purple sulfur bacterium, resembles aerobic bacterial cells in that it has an nadp-thioredoxin system composed of a single thioredoxin which is reduced by nadph via nadp-thioredoxin reductase. both protein components were purified to homogeneity, and some of their properties were determined. chromatium vinosum thioredoxin was slightly larger than other bacterial thioredoxins (13 versus 12 kilodaltons) but was similar in its specificity (ability to a ... | 1984 | 6373736 |
| computed spatial homology between the l12 protein of chloroplast ribosome and 1.7 a structure of escherichia coli l12 domain. | a computer-graphic model of the tertiary structure of a functional domain in an organelle ribosomal protein was generated using the amino acid sequence of chloroplast ribosomal protein l12 from spinach (bartsch, kimura and subramanian, proc. natl. acad. sci. usa 79, 6871-6875, 1982) and 1.7 a resolution coordinates of the e. coli l12 c-terminal fragment crystal (leijonmarck, eriksson and liljas, nature 286, 824-826, 1980). a comparison between the model and the experimentally derived structure s ... | 1984 | 6383397 |
| copper facilitated chemiluminescence from the sulfhydryl proteins: yeast alcohol dehydrogenase, spinach ferredoxin and metallothionein. | this paper describes a copper mediated formation of active oxygen, presumably o2, from the sulfhydryl proteins, yeast alcohol dehydrogenase spinach ferredoxin and rabbit liver metallothionein which, on the addition of cyanide in the presence of acetaldehyde, displays as a chemiluminescence. these studies may provide some insights into the mechanisms of copper toxicity and provide a sensitive assay for monitoring the presence of sulfhydryl groups. | 1984 | 6391488 |
| comparison of in vitro and in vivo measurements of dietary ca exchangeability and bioavailability. | an in vitro method for measuring dietary mineral exchangeability (miscibility with an extrinsic isotopic tracer) was tested by comparison with in vivo measurements in rats. collards, spinach and soybeans, intrinsically labeled with 45ca, were fed to rats together with extrinsically added 47ca. absorption of both tracers was determined by measuring their concentrations in the femur 2 days after consumption of the labeled test meals. the same intrinsically and extrinsically labeled foods were dige ... | 1983 | 6401805 |
| isolation and sequencing of an active-site peptide from rhodospirillum rubrum ribulosebisphosphate carboxylase/oxygenase after affinity labeling with 2-[(bromoacetyl)amino]pentitol 1,5-bisphosphate. | 2-[(bromoacetyl)amino]pentitol 1,5-bisphosphate was reported to be a highly selective affinity label for ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum [fraij, b., & hartman, f. c. (1982) j. biol. chem. 257, 3501-3505]. the enzyme has now been inactivated with a 14c-labeled reagent in order to identify the target residue at the sequence level. subsequent to inactivation, the enzyme was carboxymethylated with iodoacetate and then digested with trypsin. the only radioactive ... | 1983 | 6404301 |
| the isocitrate dehydrogenase from cyanobacteria. | the present communication describes the properties of isocitrate dehydrogenase in crude extracts from the unicellular anacystis nidulans and from heterocysts and vegetative cells of nostoc muscorum and anabaena cylindrica. the activity levels of this enzyme are much higher in heterocysts than in vegetative cells of n. muscorum and a. cylindrica. isocitrate dehydrogenase is virtually inactive in vegetative cells of a. cylindrica. the enzyme is negatively regulated by the reduction charge and scar ... | 1983 | 6409049 |
| kinetic studies on reactions of iron-sulphur proteins. oxidation of the reduced form of spirulina platensis [2fe-2s] ferredoxin with inorganic complexes. | kinetic results are presented for the reaction of reduced [2fe-2s] ferredoxin from the blue-green alga spirulina platensis with co(nh3)6(3+), co(edta)- and co(acac)3 as oxidants at ph 8.0 at i0.10 (nacl). the aim is to compare results obtained with those previously reported for the [2fe-2s] ferredoxin from parsley, where the two ferredoxins under consideration are in evolutionary terms widely divergent (35% amino acid variations). the three oxidants chosen have different ligand sets and differen ... | 1983 | 6409090 |
| spirulina ferredoxin-nadp+ reductase. further characterization with an improved preparation. | the preparation procedure for spirulina ferredoxin-nadp+ reductase (ferredoxin: nadp+ oxidoreductase, ec 1.18.1.2, fnr) was improved by adding protease inhibitors, phenylmethylsulfonylfluoride (pmsf) and edta, through the whole process of preparation and by introducing an affinity chromatography step on blue sepharose cl-6b. the addition of the inhibitors largely prevented the formation of the minor component (fnr i), and the affinity gel chromatography simplified the preparation process, shorte ... | 1983 | 6415047 |
| classification of iron-sulfur cores in ferredoxins by 1h nuclear magnetic resonance spectroscopy. | a 1h nuclear magnetic resonance (nmr) study was carried out on various ferredoxins which possess one of three types of iron-sulfur clusters, (2fe-2s), (3fe-3s), or (4fe-4s). in the isolated form, (2fe-2s) ferredoxins from spinach (spinacea oleracia), pokeweed (phytolacca americana), a blue-green alga (spirulina platensis), and a halobacterium (halobacterium halobium) exhibited two broad resonances common in chemical shift at the region downfield of 10 ppm. in their reduced forms, seven contact-s ... | 1983 | 6417123 |
| inhibition of ribulose bisphosphate carboxylase by substrate ribulose 1,5-bisphosphate. | substrate ribulose bisphosphate is a potent and a weak inhibitor of the rate of co2/mg2+ activation in the carboxylase purified from spinach leaves and rhodospirillum rubrum, respectively. at 2 degrees c, the concentration of ribulose bisphosphate required for 50% inhibition of the initial rate of co2/mg2+ activation was less than 0.4 microm for the spinach enzyme, but between 67 and 270 microm for the r. rubrum carboxylase. activator 14co2 trapping experiments demonstrated that ribulose bisphos ... | 1983 | 6417133 |
| isolation and characterization of the cytosolic and chloroplast forms of spinach leaf fructose diphosphate aldolase. | two different isoenzymes of fructose-p2 aldolase can be resolved by chromatography of crude spinach leaf extracts on deae-cellulose columns. the acidic isoenzyme comprises about 85% of the total leaf aldolase activity. the two forms differ in primary structure as judged by their distinctive amino acid compositions, tryptic peptide patterns, and immunological properties. only the acidic isoenzyme was detected in extracts of isolated chloroplasts, suggesting that this molecule represents the chlor ... | 1984 | 6420397 |
| 2-(4-bromoacetamido)anilino-2-deoxypentitol 1,5-bisphosphate, a new affinity label for ribulose bisphosphate carboxylase/oxygenase from rhodospirillum rubrum. determination of reaction parameters and characterization of an active site peptide. | a new affinity label for ribulose bisphosphate carboxylase/oxygenase from rhodospirillum rubrum, 2-(4-bromoacetamido)anilino-2-deoxypentitol 1,5-bisphosphate, has been prepared, reductive amination of ribulose-p2 with p-phenylenediamine in the presence of sodium cyanoborohydride yielded an epimeric mixture which was resolved by chromatography on quaternary aminoethyl-sephadex. subsequent bromoacetylation of the isolated amino bisphosphates gave reagents a and b (ribo and arabino epimers of 2-(4- ... | 1984 | 6421817 |
| temperature dependence of the resonance raman spectra of plastocyanin and azurin between cryogenic and ambient conditions. | resonance raman spectra of spinach plastocyanin and pseudomonas aeruginosa azurin were studied as a function of temperature between 10 k and 300 k. the spectra are markedly improved both in signal/noise ratio and in resolution at low temperatures. the assignments of the resonance raman-active vibrations are reinterpreted in view of the number and intensities of peaks observed in the low-temperature spectra. features appear in the low-temperature spectra of azurin that may be due to copper-bound ... | 1984 | 6422471 |
| the shape of ribulose bisphosphate carboxylase/oxygenase in solution as inferred from small angle neutron scattering. | small angle neutron scattering of both activated and deactivated hexadecameric ribulose bisphosphate carboxylase/oxygenase from spinach revealed that its structure in solution very closely resembles that determined for the deactivated crystalline enzyme from tobacco (baker, t.s., eisenberg, d., and eiserling, f. (1977) science 196, 293-295). scattering from both forms of the enzyme in h2o most closely fits that expected from a hollow sphere with an outer radius of 56.4 a and inner radius of 14.3 ... | 1984 | 6423629 |
| x-ray diffraction studies on photosystem i fragments from a blue-green alga, anabaena variabilis, and spinach. | photosystem i fragments were prepared from thylakoid membranes of a blue-green alga (anabaena variabilis) and spinach by treatment with a detergent, triton x-100. equatorial x-ray diffraction patterns were recorded on films for oriented specimens of thylakoid membranes and photosystem i fragments. the thylakoid membranes and photosystem i fragments gave essentially the same equatorial diffraction patterns in both anabaena variabilis and spinach, indicating that the major x-ray scatterers in thes ... | 1984 | 6425276 |
| effect of al3+ on electron transport catalysed by photosystem i & ii of photosynthesis in cyanobacterium synechococcus spheroplasts & beet-spinach chloroplasts. | | 1983 | 6427098 |
| intermediates in the ribulose-1,5-bisphosphate carboxylase reaction. | at least two intermediates of the d-ribulose-1,5-bisphosphate carboxylase/oxygenase (ec 4.1.1.39) reaction were liberated in detectable amounts when the functioning enzyme from rhodospirillum rubrum was quenched in acid. using substrate labeled with 32p in c-1, [32p]orthophosphate (pi) was found when the quenched solution was rapidly processed for extraction of pi as the acid molybdate complex. reaction with sodium borohydride under mildly alkaline conditions immediately after acid quenching of ... | 1984 | 6427222 |
| origins and molecular evolution of the carbonic anhydrase isozymes. | work on membrane-bound and subcellular forms of ca at the protein level, and the possibility of multiple forms of the mouse ca ii gene at the dna level, indicate that ca may represent an extensive multigene family. a method for classifying newly sequenced ca molecules, or genes encoding them, is discussed. phylogenetic trees based on the existing sequence data are presented and discussed in terms of gene evolution. the active-site residues of ca ii have been more conserved in evolution than thos ... | 1984 | 6430173 |
| complete primary structure of ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum. | of the 14 cyanogen bromide fragments derived from rhodospirillum rubrum ribulosebisphosphate carboxylase/oxygenase, four are too large to permit complete sequencing by direct means [f. c. hartman, c. d. stringer, j. omnaas, m. i. donnelly, and b. fraij (1982) arch. biochem. biophys. 219, 422-437]. these have now been digested with proteases, and the resultant peptides have been purified and sequenced, thereby providing the complete sequences of the original fragments. with the determination of t ... | 1984 | 6430239 |
| enzymic synthesis of the iron-sulfur cluster of spinach ferredoxin. | a biologically active spinach ferredoxin was reconstituted from the apoprotein by incubation with catalytic amounts of the sulfurtransferase rhodanese in the presence of thiosulfate, reduced lipoate and ferric ammonium citrate. analytical and spectroscopical features of the reconstituted ferredoxin were identical to those of the native one; yield of the reconstitution reaction was 80%. yields and kinetic parameters of the enzymic and chemical reconstitution were also compared. the higher efficie ... | 1984 | 6430704 |
| spirulina ferredoxin-nadp+ reductase. the complete amino acid sequence. | the amino acid sequence of ferredoxin-nadp+ oxidoreductase [ec 1.18.1.2, fnr] from spirulina sp., a blue-green alga, was determined. spirulina ferredoxin-nadp+ oxidoreductase was composed of 294 amino acid residues and the molecular weight of the holoenzyme was 34,135. an apparent homology of the amino(n)-terminal region was found between ferredoxin-nadp+ reductases from spirulina and spinach. we also found some sequence similarities in human erythrocyte glutathione reductase and p-hydroxybenzoa ... | 1984 | 6430889 |
| phylogeny of the 5s ribosomal rna from synechococcus lividus ii: the cyanobacterial/chloroplast 5s rnas form a common structural class. | the complete nucleotide sequence of the 5s ribosomal rna from the cyanobacterium synechococcus lividus ii has been determined. the sequence is (sequence in text) this 5s rna has the cyanobacterial- and chloroplast-specific nucleotide insertion between positions 30 and 31 (using the numbering system of the generalized eubacterial 5s rna) and the chloroplast-specific nucleotide-deletion signature between positions 34 and 39. the 5s rna of s. lividus ii has 27 base differences compared with the 5s ... | 1984 | 6443313 |
| examination of protein sequence homologies: i. eleven escherichia coli l7/l12-type ribosomal "a" protein sequences from eubacteria and chloroplast. | seven complete and four partial sequences of escherichia coli l7/l12-type ribosomal "a" proteins obtained from various bacteria (e. coli, bacillus subtilis, micrococcus lysodeikticus, rhodopseudomonas spheroides, desulfovibrio vulgaris, streptomyces griseus, bacillus stearothermophilus, clostridium pasteurianum, arthrobacter glacialis, and vibrio costicola) and spinach chloroplast have been reexamined using a computer program that searches for homologous tertiary structures. comparison matrices ... | 1984 | 6443314 |
| nucleotide sequence of a spinach chloroplast valine trna. | the nucleotide sequence of a spinach chloroplast valine trna (sp. chl. trna val) has been determined. this trna shows essentially equal homology to prokaryotic valine trnas (58-65% homology) and to the mitochondrial valine trnas of lower eukaryotes (yeast and n. crassa, 61-62% homology). sp. chl. trna val shows distinctly lower homology to mouse mitochondrial valine trna (53% homology) and to eukaryotic cytoplasmic valine trnas (47-53% homology). sp. chl. trna val, like all other chloroplast trn ... | 1981 | 6456449 |
| [nitrate content in the soils and vegetable crops in the villages of one district]. | the authors determine the content of nitrates in soil samples and the vegetables grown on them (lettuce, spinach, onion, garlic) via sensitive spectrophotometric methods with phenodisulphonic acid and reduction with cadmium column. the lowest nitrates content was established in the soil samples and vegetables grown by aic, followed by the private arms, and the highest - in the green-horse vegetables and soil samples, owing mainly to the technology of production. | 1984 | 6483820 |
| the primary structure of spinach acyl carrier protein. | acyl carrier protein (acp) from spinach leaves has been purified to homogeneity by high-performance liquid chromatography with an anion-exchange column. the amino acid sequence of one major acp in spinach leaves, acp-i, has been determined by automated edman degradation. it consists of the following 82 amino acids: (sequence in text). sequencing of the intact polypeptide provided data for the first 57 residues. cleavage of the succinylated acp with cnbr at met-46, followed by sequencing of the f ... | 1984 | 6486822 |
| the effect of hypolipidemic drugs on plant lipid metabolism. | the effect of hypolipidemic drugs, wy14643 and dh990, on plant lipid metabolism has been studied. the total incorporation of [14c]acetate into lipids was inhibited by addition of both drugs to aged potato (solanum tuberosum) tuber discs, spinach (spinacia oleracea) leaves, and spinach chloroplasts, while the incorporation in chlorella vulgaris cells was affected only by dh990. moreover, dh990 inhibited the incorporation of 14c-labeled fatty acids into phosphatidylcholine and phosphatidylethanola ... | 1984 | 6486826 |
| absorption kinetics of oxalate from oxalate-rich food in man. | the absorption of oxalate was investigated in a healthy subject after ingestion of oxalate-rich meals (spinach and rhubarb) with and without addition of 14c-labeled oxalic acid and calcium oxalate, and after oxalate-free meals with addition of nonlabeled sodium oxalate and calcium oxalate. under these conditions, calcium oxalate was absorbed to the same extent as soluble oxalate; only a small percentage (2.4 +/- 0.7) of the total oxalate load was absorbed. significant oxalate absorption occurred ... | 1984 | 6496379 |
| sequence organization of a pea chloroplast dna gene coding for a 34,500-dalton protein. | a gene (pgii), which codes for a 34.5-kilodalton protein, has been isolated and cloned from pea chloroplast dna. the production of its 1.2-kilobase mrna is photodependent. the direction of transcription has been determined, the site of initiation of transcription has been found, and an in vitro protein product has been produced. the gene, including the 5' and 3'-flanking regions, has been sequenced. it shows ca. 95% homology to the photosystem ii thylakoid membrane protein, photogene 32, from sp ... | 1984 | 6513932 |
| chromatographic separation of extruded iron-sulfur cores from the apoproteins of clostridium pasteurianum and spinach ferredoxins in aqueous triton x-100/urea. | iron-sulfur core extrusions from spinach [( 2fe-2s]) and clostridium pasteurianum (2[4fe-4s]) ferredoxins in aqueous triton x-100/urea containing excess benzenethiol yield quantitatively [fensn(sph)4]2- with n = 2 and n = 4, respectively. the iron-sulfur cluster can be separated from the corresponding apoprotein by rapid passage of the extrusion mixture over a small anaerobic column of whatman de-52 anion-exchange cellulose. essentially quantitative recovery of [fensn (sph)4]2- is achieved in th ... | 1984 | 6517316 |
| thylakoid membranes: the translational site of chloroplast dna-regulated thylakoid polypeptides. | stromal ribosomes and those bound to thylakoid membranes were prepared from intact spinach chloroplasts which were purified on percoll gradients. the products of read-out translation of these ribosomes supplemented with an escherichia coli extract were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. striking similarity was found between the polypeptides labeled in the read-out translation of the chloroplastic ribosomes and those synthesized in isolated chloroplasts. among ... | 1984 | 6517602 |
| unscheduled dna synthesis in human leucocytes after a fish (amine source) meal with or without salad (nitrite source). | increased unscheduled dna synthesis (uds) was observed previously in leucocytes from human volunteers after various meals containing nitrite from cured meats and vegetables. to explore further the role of ingested nitrite, uds response was measured in human leucocytes after a meal of bread, butter and cod fish alone (amine source) or bread, butter and cod fish plus a salad of lettuce, radish and spinach (nitrite source). a cross-over design was used so that all subjects (10 male, 10 female) were ... | 1984 | 6533054 |
| survey of fresh vegetables for nematodes, amoebae, and salmonella. | contamination by nematodes, amoebae, and bacteria of the genus salmonella was estimated in a 2-year survey of salad vegetables obtained from wholesale and retail sources. the vegetables examined were cucumbers, cabbage, lettuce, celery, carrots, radishes, tomatoes, mushrooms, cauliflower, and spinach. nematode eggs and larvae were recovered by the nacconol-ether centrifugation method. some nematode eggs were identified as parasitic ascaris sp.; the majority of larval nematodes were thought to be ... | 1984 | 6540260 |
| adaptation of plants to atmospheric pollutants. | man-made air pollutants are a recent phenomenon in the evolutionary experience of plants and animals although natural air pollutants from volcanic eruptions, forest fires and dust storms have accompanied evolution for geological eras. plants have responded to increasing concentrations of such pollutants as sulphur dioxide, fluorides, photochemical oxidants and acid rain at the community, species, population and individual levels. the lichens and bryophytes have shown particularly dramatic change ... | 1984 | 6559120 |
| interaction of ribulose bisphosphate carboxylase/oxygenase with 2-carboxyhexitol 1,6-bisphosphates. | 2-c-carboxy-d-glucitol 1,6-bisphosphate (cgbp) and 2-c-carboxy-d-mannitol 1,6-bisphosphate (cmbp) have been synthesized, isolated, and the structures of these compounds and the derived lactones elucidated by nmr spectroscopy and periodate oxidation. both carboxyhexitol bisphosphates, which are homologs of the transition state analog 2-c-carboxy-d-arabinitol 1,5-bisphosphate, exhibit competitive inhibiton of ribulose bisphosphate carboxylase/oxygenase (ec 4.1.1.9) isolated from spinach (spinacia ... | 1983 | 6573158 |
| purification, subunit structure and immunological comparison of fructose-bisphosphate aldolases from spinach and corn leaves. | the cytosol and chloroplast fructose-bisphosphate aldolases from spinach leaves were separated by ion-exchange chromatography on deae-cellulose, and were purified by subsequent affinity chromatography on phosphocellulose to apparent homogeneity as judged from polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. the two aldolases had specific activities of 7.2 and 7.8 units mg protein-1. molecular weight determinations by electrophoresis in sodium dodecyl sulfate gels and ... | 1983 | 6617652 |
| plant seeds contain several thioredoxins of regular size. | thioredoxin systems composed of several thioredoxin isoproteins and a nadph: thioredoxin reductase are contained in the albumin-globulin fraction of wheat and soy-bean seed proteins. two wheat thioredoxins i and ii were separated on cm-cellulose whereas soy-bean extracts could be resolved into three thioredoxins i, ii, and iii on deae-cellulose. these proteins were purified to apparent homogeneity and were shown by sodium dodecylsulfate/polyacrylamide gel electrophoresis to possess the molecular ... | 1983 | 6682037 |
| an examination of human blood for the presence of volatile nitrosamines. | human blood was examined for the presence of volatile nitrosamines. nitrosamines were detected by chemiluminescence and mass spectrometry after separation from blood by distillation and solvent extraction. n-nitrosodimethylamine was detected in all but one of 51 blood samples taken from 23 different people, at concentrations from the detection limit (0.1 microgram/litre) to 1.4 microgram/litre with a mean concentration of 0.5 microgram/litre. n-nitrosodiethylamine was detected in 11 samples, the ... | 1983 | 6682077 |
| immuno chemical characterization of nitrate reductase from spinach leaves and roots. | nitrate reductase from spinach (spinacia oleracea l.) leaves was purified to homogeneity and specific antibodies against the protein were raised by the immunization of rabbits. using immunodiffusion and immunoprecipitation techniques, the enzymes from leaves and roots were compared. it was demonstrated that the two nitrate reductases were different proteins on the basis of their antigenic behaviour. | 1983 | 6683506 |
| [studies of dietary influence on urinary oxalate in calcium oxalate stone formers]. | in order to examine the effect of diet on the urinary excretion of oxalate, a spinach loading and milk loading experiment was performed in normal subjects and patients with single calcium oxalate stones and recurrent calcium oxalate stones after a rat experiment. when spinach (100 g, total oxalate 642.57 mg, insoluble oxalate 282.21 mg, taken oxalate 444.57 mg) was given with a low calcium diet to the patients, the increase of urinary oxalate was more prominent in those with recurrent stones; th ... | 1983 | 6687143 |
| cellular fructose-p2 aldolase has a derivatized (blocked) nh2 terminus. | fructose-p2 aldolases isolated from vertebrate skeletal muscle have underivatized nh2-terminal proline residues in contrast to most other cytoplasmic proteins which contain alpha-n-acetylated termini. however, if "native" aldolase molecules derived from chicken muscle, rat liver, wheat germ, and the cytosol of spinach leaves are isolated in the presence of phenylmethanesulfonyl fluoride (an inhibitor of serine proteases), they contain blocked and presumably derivatized nh2-terminal residues. whe ... | 1984 | 6693379 |