Publications

the amino acid sequence of the spinach basic cupredoxin plantacyanin.	we describe the amino acid sequence of plantacyanin isolated from spinach leaves. this small basic copper-binding plant cupredoxin contains 91 amino acids (accession no. s70746) and its theoretical average mass of 9788.2 da was confirmed by electrospray ionization mass spectrometry. when compared to the sequences of other plant cupredoxins, the most similar homologs were cucumber basic blue protein and stellacyanin from laquer tree with 44-58% identical residues. other known plant cupredoxins we ...	1996	8955876
an arabidopsis thaliana cdna encoding ps ii-x, a 4.1 kda component of photosystem ii: a bipartite presequence mediates seca/delta ph-independent targeting into thylakoids.	higher plant photosystem ii preparations contain a 4.1 kda polypeptide (subunit x) associated with the oxygen-evolving core complex. we describe the isolation of a cdna encoding ps ii-x from arabidopsis thaliana, in which the c-terminal region is highly homologous to partially sequenced ps ii-x from wheat and spinach. the mature protein of 42 residues is preceded by a 74-residue, bipartite presequence similar to those involved in the targeting of nuclear-encoded thylakoid lumen proteins, althoug ...	1996	8706853
genetic mapping of genes for twelve nuclear-encoded polypeptides associated with the thylakoid membranes in beta vulgaris l.	thylakoid membranes of chloroplasts are composed of approx. 75 polypeptide species. nearly 60% originate in nuclear genes, the remainder in plastid genes. in order to localize representatives of the nuclear-encoded gene complement in a eukaryotic plant genome (sugar beet, beta vulgaris l.), we have investigated the rflp patterns of 21 cdnas from spinach that code for thylakoid proteins or proteins peripherally associated with thylakoid membranes. differences in gene dosage were noted between bot ...	1996	8849689
clastogenic activity of pure chlorophyll and anticlastogenic effects of equivalent amounts of crude extract of indian spinach leaf and chlorophyllin following dietary supplementation to mice.	dietary consumption of green vegetables has been associated with protection against mutagenic and clastogenic activity of genotoxicants. chlorophyll, being present in all green plants, had earlier been suggested to be the principal factor involved. mice were administered (i) crude aqueous extract of leaf of indian spinach, beta vulgaris l. var.benghalensis hort., and equivalent amounts of (ii) chlorophyll extracted from the leaf; (iii) purified chlorophyll, (iv) chlorophyllin, a sodium-copper de ...	1996	8844993
effects of composting on phytotoxicity of spent pig-manure sawdust litter.	the phytotoxicity of spent pig-manure sawdust litter (spent litter) was evaluated during further composting. aqueous extracts of the spent litter were prepared by shaking the sample with water (1:10 w/v), and the toxicity of these extracts was determined on relative seed germination, relative root elongation and germination index (gi, a factor of relative seed germination and relative root elongation). the sensitivity of six plant species, namely brassica parachinensis (chinese cabbage), brassic ...	1996	15093523
expression of active spinach glycolate oxidase in aspergillus nidulans.	the biocatalytic production of glyoxylic acid from glycolic acid requires two enzymes: glycolate oxidase, which catalyzes the oxidation of glycolic acid by oxygen to produce glyoxylic acid and hydrogen peroxide, and catalase, which decomposes the byproduct hydrogen peroxide. as an alternative to isolation from the leaf peroxisomes of spinach, glycolate oxidase has now been cloned and expressed in transformants of aspergillus nidulans t580 at levels ranging from 1.7 to 36 iu/g dry wt. cells. the ...	1996	18626962
a comparative thermodynamic analysis by laser-flash absorption spectroscopy of photosystem i reduction by plastocyanin and cytochrome c6 in anabaena pcc 7119, synechocystis pcc 6803 and spinach.	a comparative thermodynamic analysis of photosystem i (psi) reduction by plastocyanin (pc) and cytochrome c6 (cyt) has been carried out by laser-flash absorption spectroscopy in the cyanobacteria anabaena pcc 7119 and synechocystis pcc 6803 as well as in spinach. these three organisms have been reported to exhibit different reaction mechanisms [hervas, m., navarro, j. a.. díaz, a., bottin, h., & de la rosa, m. a. (1995) biochemistry, 34, 11321-11326]. whereas the activation free energy for the o ...	1996	8611575
function of the [2fe-2s] cluster in mammalian ferrochelatase: a possible role as a nitric oxide sensor.	ferrochelatase (e.c. 4.99.1.1) is the terminal enzyme of the heme biosynthetic pathway, catalyzing the insertion of ferrous iron into protoporphyrin. in mammals the enzyme contains a labile [2fe-2s] center. although this cluster is absent in all prokaryotic, plant, and yeast ferrochelatases, its destruction or elimination from the mammalian enzyme results in loss of enzyme activity. in the current study we present data which clearly demonstrate that mammalian ferrochelatase is strongly inhibited ...	1996	8611576
mutations of glu92 in ferredoxin i from spinach leaves produce proteins fully functional in electron transfer but less efficient in supporting nadp+ photoreduction.	ferredoxin i in spinach chloroplasts fulfils the role of distributing electrons of low redox potential produced by photosystem i to several metabolic routes, nadp+ reduction being the major output. to investigate the role of glu92, which is conserved in the chloroplast-type ferredoxins, mutations of this residue to either gln, ala or lys were obtained through site-directed mutagenesis. a glu93ala mutant was also designed. the four mutants of ferredoxin i were overproduced in escherichia coli, pu ...	1996	8612617
purification, metal cofactor, n-terminal sequence and subunit composition of a 5-aminolevulinic acid dehydratase from the unicellular green alga scenedesmus obliquus, mutant c-2a'.	5-aminolevulinic acid dehydratase was purified to apparent homogeneity from scenedesmus obliquus, mutant c-2a', starting with serial affinity chromatography according to wang et al., followed by separation on deae-cellulose de 52, tskgel toyopearl hw-55 and fplc on mono q. the enzyme was purified 117-fold compared with the initial crude soluble enzyme preparation and showed a final specific activity of 9.17 microkat/kg protein at ph 8.2 at a total recovery of 7%. mg2+ was determined to be the me ...	1996	8612634
recombinant human cytochrome p450 1a2 and an n-terminal-truncated form: construction, purification, aggregation properties, and interactions with flavodoxin, ferredoxin, and nadph-cytochrome p450 reductase.	previous work from this laboratory indicated that the n-terminus of recombinant human cytochrome p450 (p450) 1a2 expressed in escherichia coli is blocked (p. sandhu, z. guo, t. baba, m. v. martin, r. h. tukey, and f. p. guengerich, (1994) arch. biochem. biophys. 30, 168 -177). a modification of this construct was done to insert an extra 12 residues containing a thrombin-sensitive site just beyond the most n-terminal hydrophobic segment, and the protein was expressed, purified, and cut with throm ...	1996	8615680
spectroscopic and kinetic properties of a recombinant form of the flavin domain of spinach nadh: nitrate reductase.	the c-terminal 268 residues of the spinach assimilatory nadh:nitrate reductase amino acid sequence that correspond to the flavin-containing domain of the enzyme have been selectively amplified and expressed as a recombinant protein in escherichia coli. the recombinant protein, which was produced in both soluble and insoluble forms, was purified to homogeneity using a combination of ammonium sulfate precipitation, affinity chromatography on 5'-adp-agarose and fplc gel filtration. the purified dom ...	1996	8615685
spinach chloroplast atp-dependent endopeptidase: ti-like protease.	the soluble fraction of spinach chloroplast was used for purification and characterization of an atp-dependent protease. purification included q sepharose fast flow, hydroxylapatite and fplc superose 6 column chromatography. the isolated enzyme requires atp and mg2+ for stimulation and represents a ubiquitin independent serine protease, containing essential sulphydryl group(s). by using fluorogenic peptides a similarity of chloroplast protease to escherichia coli ti protease was observed. the ch ...	1996	8588875
voltammetry of plastocyanin at a graphite electrode: effects of structure, charge, and electrolyte.	comparative voltammetric studies on anabaena variabilis plastocyanin (positively charged at neutral ph) and spinach and poplar plastocyanins (negatively charged at neutral ph) have been undertaken at an edge-plane graphite electrode as a function of ionic strength, ph, and mg(2+) concentration at 3 degrees c. the aim was to provide a more detailed understanding of the influence of the electrode-protein (solution) interfacial characteristics, as well as the variation of the formal potential with ...	1996	11666900
245 ghz high-field epr study of tyrosine-d zero and tyrosine-z zero in mutants of photosystem ii.	a 245 ghz 8.7 t high-field epr study of tyrosine-d (tyrd zero) and tyrosine-z (tyrz zero) radicals of photosystem ii (psii) from synechocystis pcc 6803 was carried out. identical principal g values for the wild-type synechocystis and spinach tyrd zero showed that the two radicals were in similar electrostatic environments. by contrast, the principal g values of the tyrd zero in the d2-his189gln mutant of synechocystis were different from those of the wild-type and spinach radicals and were simil ...	1996	8547247
differential effects of n- and c-terminal deletions on the two activities of rubisco activase.	spinach (spinacea oleracea) leaf ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) activase was subjected to limited proteolysis with trypsin and directed deletions were made by modifying the spinach rubisco activase cdna and expressing the 41-kda isoform in escherichia coli. protein exposed to trypsin displayed a more rapid loss of the ability to promote the activation of decarbamylated rubisco than atp hydrolysis (e.g., 10 and 50% activity remaining, respectively, after 1 h). a series ...	1996	8579356
the spinach atpc and atpd genes contain elements for light-regulated, plastid-dependent and organ-specific expression in the vicinity of the transcription start sites.	run-on assays with isolated nuclei demonstrate that the transcription rates of atpc and atpd (gene products: the cf1 subunits gamma and delta of the chloroplast atp synthase) are comparable in spinach seedlings. however, chimeric gus gene fusions with 5'-flanking regions of the atpc gene direct an approximately 10-fold lower gus level in transgenic tobacco compared with equivalent fragments from the atpd gene. both promoters contain sequences in the vicinity of the respective tata boxes, which a ...	1996	8580971
high-level expression, purification, and crystallization of recombinant spinach glycolate oxidase in escherichia coli.	glycolate oxidase is a flavin-dependent enzyme in the photorespiratory pathway in plants. here we report the heterologous expression of glycolate oxidase in escherichia coli and an isolation procedure which results in 4 mg pure protein per gram cell paste in only 1.5 days. this corresponds to a more than 50-fold improvement in yield compared to previously reported expression systems. the purified recombinant protein can be crystallized easily, and the crystals are isomorphous to those obtained f ...	1996	8936590
characterization and crystallization of the lumen side domain of the chloroplast rieske iron-sulfur protein.	a soluble, 139-residue cooh-terminal polypeptide fragment of the rieske iron-sulfur protein of the cytochrome b6f complex from spinach chloroplasts was obtained by limited proteolysis of the complex and a two-step chromatography purification protocol. the purified rieske iron-sulfur protein fragment was characterized by: (i) a single nh2-terminal sequence, nh2-phe-val-pro-pro-gly-gly, starting with residue 41 of the intact rieske protein; (ii) a single molecular weight species determined by mass ...	1996	8940143
glutamate 94 of [2fe-2s]-ferredoxins is important for efficient electron transfer in the 1:1 complex formed with ferredoxin-glutamate synthase (glts) from synechocystis sp. pcc 6803.	we have analyzed the role of critical amino acid residues involved in the interaction between ferredoxin and ferredoxin-glutamate synthase (gogat) encoded by the glts gene from the cyanobacterium synechocystis sp. pcc 6803. our results indicated that the glutamate 94 residue of anabaena 7120 ferredoxin (= e92 of the synechocystis 6803 ferredoxin) was necessary for an efficient electron transfer to gogat comparable to ferredoxin:nadp-reductase, nitrite reductase and nitrate reductase [schmitz and ...	1996	8950376
is e37, a major polypeptide of the inner membrane from plastid envelope, an s-adenosyl methionine-dependent methyltransferase?	using antibodies raised against e37, one of the major polypeptides of the inner membrane from the chloroplast envelope, it has been demonstrated that a single immunologically related polypeptide was present in total protein extracts from various higher plants (monocots and dicots), in photosynthetic and non-photosynthetic tissues from young spinach plantlets, as well as in the cytoplasmic membrane from the cyanobacteria synechococcus. this ubiquitous distribution of e37 strongly suggests that th ...	1996	8953251
intron sequences are involved in the plastid- and light-dependent expression of the spinach psad gene.	plastid- and light-regulated expression of the spinach psad gene in transgenic tobacco requires sequences downstream of the transcription start site, sand promoter sequences alone are not sufficient to respond to these stimuli. the spinach psad mrna level in transgenic tobacco is still plastid- and light-responsive when the expression of the intron-containing transcription unit is driven by the 35s rna camv promoter indicating that psad contains (a) gene-internal control element(s). if the genom ...	1996	8953253
studies on protein processing for membrane-bound spinach leaf mitochondrial processing peptidase integrated into the cytochrome bc1 complex and the soluble rat liver matrix mitochondrial processing peptidase.	the plant mitochondrial processing peptidase (mpp) that catalyses the cleavage of the presequences from precursor proteins during or after protein import is a membrane-bound enzyme that constitutes an integral part of the bc1 complex of the respiratory chain. in contrast, mpp from mammals is soluble in the matrix space and does not form part of the respiratory chain. in the present study, we have compared the substrate specificity of the isolated spinach leaf bc1/mpp with rat liver mpp using syn ...	1996	8954161
the mechanism of gt element-mediated cell type-specific transcriptional control.	promoter studies have revealed that sequences related to the gt-1 binding site, known as gt elements, are conserved in plant nuclear genes of diverse functions. in this work, we addressed the issue of whether gt elements are involved in cell type-specific transcriptional regulation. we found that the inactivation of gt-1 site-mediated transcription in roots is correlated with the absence of the gt-1 binding activity in root extracts. in addition, the mutation of the related gt-1 (from the pea rb ...	1996	8955086
cross-linking of engineered subunit delta to (alphabeta)3 in chloroplast f-atpase.	ser --> cys mutations were introduced into subunit delta of spinach chloroplast f0f1-atpase (cf0cf1) by site-directed mutagenesis. the engineered delta subunits were overexpressed in escherichia coli, purified, and reassembled with spinach chloroplast f1-atpase (cf1) lacking the delta subunit (cf1(-delta)). by modification with eosin-5-maleimide, it was shown that residues 10, 57, 82, 160, and 166 were solvent-accessible in isolated cf1 and all but residue 166 also in membrane-bound cf0cf1. modi ...	1996	8955107
identification of a chloroplast coenzyme a-binding protein related to the peroxisomal thiolases.	a 30-kd coenzyme a (coa)-binding protein was isolated from spinach (spinacea oleracea) chloroplast soluble extracts using affinity chromatography under conditions in which 95% of the total protein was excluded. the 30-kd protein contains an eight-amino-acid sequence, dvrlyyga, that is identical to a region in a 36-kd protein of unknown function that is encoded by a kiwifruit (actinidia deliciosa) cdna. southern blotting also detected a spinach gene that is related to the kiwifruit cdna. the kiwi ...	1996	8972603
molecular characterization of transketolase (ec 2.2.1.1) active in the calvin cycle of spinach chloroplasts.	a cdna encoding the calvin cycle enzyme transketolase (tkl; ec 2.2.1.1) was isolated from sorghum bicolor via subtractive differential hybridization, and used to isolate several full-length cdna clones for this enzyme from spinach. functional identity of the encoded mature subunit was shown by an 8.6-fold increase of tkl activity upon induction of escherichia coli cells that overexpress the spinach tkl subunit under the control of the bacteriophage t7 promoter. chloroplast localization of the cl ...	1996	8980496
functional studies of chloroplast glyceraldehyde-3-phosphate dehydrogenase subunits a and b expressed in escherichia coli: formation of highly active a4 and b4 homotetramers and evidence that aggregation of the b4 complex is mediated by the b subunit carboxy terminus.	chloroplast glyceraldehyde-3-phosphate dehydrogenase (phosphorylating, e.c. 1.2.1.13) (gapdh) of higher plants exists as an a2b2 heterotetramer that catalyses the reductive step of the calvin cycle. in dark chloroplasts the enzyme exhibits a molecular mass of 600 kda, whereas in illuminated chloroplasts the molecular mass is altered in favor of the more active 150 kda form. we have expressed in escherichia coli proteins corresponding to the mature a and b subunits of spinach chloroplast gapdh (g ...	1996	8980499
cp12: a small nuclear-encoded chloroplast protein provides novel insights into higher-plant gapdh evolution.	higher-plant chloroplast nad(p)-glyceraldehyde 3-phosphate dehydrogenase (nad(p)-gapdh; ec 1.2.1.13) is composed of two different nuclear-encoded subunits, gapa and gapb, forming the highly active heterotetrameric a2b2 enzyme. the main difference between these two subunits is a c-terminal extension of about 30 amino acid residues of gapb. we present cdna clones for a nuclear-encoded chloroplast protein from pea, spinach and tobacco, which we have named cp12. the mature protein consists of only 7 ...	1996	8980547
molecular cloning of a cdna encoding 3-ketoacyl-acyl carrier protein synthase iii from leek.	3-ketoacyl-acyl carrier protein synthase iii (kas iii) catalyzes the initial condensation of malonyl-acyl carrier protein (acp) with acetyl-coa in plant and bacterial fatty acid biosynthesis. the first cdna clone encoding kas iii from a monocot is reported here. a cdna clone was isolated from a leek epidermal cdna library by screening with spinach and arabidopsis heterologous probes from kas iii cdna clones. when expressed in escherichia coli, the cloned enzyme was able to catalyze the expected ...	1996	8982066
recombinant hansenula polymorpha as a biocatalyst: coexpression of the spinach glycolate oxidase (go) and the s. cerevisiae catalase t (ctt1) gene.	the methylotrophic yeast hansenula polymorpha has been developed as an efficient production system for heterologous proteins. the system offers the possibility to cointegrate heterologous genes in anticipated fixed copy numbers into the chromosome. as a consequence co-production of different proteins in stoichiometric ratios can be envisaged. this provides options to design this yeast as an industrial biocatalyst in procedures where several enzymes are required for the efficient conversion of a ...	1996	8987534
isozymes of superoxide dismutase from aloe vera.	extracts from the parenchymatous leaf gel and the rind of the aloe vera plant (aloe barbadensis miller) were shown to contain seven electrophoretically-identifiable superoxide dismutases (sods). the chromatographic elution profiles and the migration of these bands on native polyacrylamide gel electrophoresis (page), for both the gel and rind, are quite similar. two of these seven activities are insensitive to cyanide treatment, suggesting that they are mangano-sods. the other five activities are ...	1996	9030888
reversible, non-denaturing metal substitution in bovine adrenodoxin and spinach ferredoxin and the different reactivities of [2fe-2s]-cluster-containing proteins.	the non-denaturing substitution of cluster iron by other metals was studied in spinach ferredoxin and in bovine adrenodoxin. only some of several metal species tested (cd2+, zn2+, vo2+, mn2+, co2+, ni2+) caused bleaching of the residual visible absorbance and of the epr signals of the reduced ferredoxins. no formation of mixed-metal cluster was observed. the most reactive metal species were cd2+ and zn2+ and cd2+ was found to react also with oxidized adrenodoxin. metal-treated proteins were reso ...	1996	8774731
the function and properties of the iron-sulfur center in spinach ferredoxin: thioredoxin reductase: a new biological role for iron-sulfur clusters.	thioredoxin reduction in chloroplasts is catalyzed by a unique class of disulfide reductases which use a [2fe-2s]2+/+ ferredoxin as the electron donor and contain an fe-s cluster as the sole prosthetic group in addition to the active-site disulfide. the nature, properties, and function of the fe-s cluster in spinach ferredoxin:thioredoxin reductase (ftr) have been investigated by the combination of uv/visible absorption, variable-temperature magnetic circular dichroism (mcd), epr, and resonance ...	1996	8784198
identification of residues of spinach thioredoxin f that influence interactions with target enzymes.	the necessity for two types of thioredoxins (trx f and m) within chloroplasts of higher plants that mediate the same redox chemistry with various target enzymes is not well understood. to approach this complex issue, we have applied site-directed mutagenesis to the identification of residues of trx f that affect its binding to and selectivity for target enzymes. based upon amino acid sequence alignments and the three-dimensional structure of escherichia coli thioredoxin, putative key residues of ...	1996	8798742
phosphorylated nitrate reductase from spinach leaves is inhibited by 14-3-3 proteins and activated by fusicoccin.	nitrate reductase (nr) in leaves is rapidly inactivated in the dark by a two-step mechanism in which phosphorylation of nr on the serine at position 543 (ser543) promotes binding to nitrate reductase inhibitor protein (nip). the eukaryotic 14-3-3 proteins bind to many mammalian signalling components (raf-1, bcr, phosphoinositide 3-kinase, protein kinase c, polyomavirus middle-t antigen and cdc25), and are implicated in the timing of mitosis, dna-damage checkpoint control, exocytosis, and activat ...	1996	8805370
the effect of sulfite on the atp hydrolysis and synthesis activities in chloroplasts and cyanobacterial membrane vesicles can be explained by competition with phosphate.	the effect of sulfite on atp synthesis and hydrolysis activities is investigated in spinach chloroplasts and in membrane vesicles from the cyanobacterium synechococcus 6716. sulfite inhibits phenazine methosulfate-mediated cyclic photophosphorylation both in thiol-modulated chloroplasts and in cyanobacterial membranes with hso3- (bisulfite) as the active ionic species. the observed inhibition is not due to inhibition of electron transfer or to uncoupling by sulfite. atp synthesis in cyanobacteri ...	1996	8806722
effect of food composition on vitamin k absorption in human volunteers.	the human vitamin k requirement is not known precisely, but the minimal requirement is often assumed to be between 0.5 and 1 x 10(-6) g/kg body weight. in the present study we addressed the question to what extent circulating vitamin k concentrations are influenced by the form in which the vitamer is consumed. the experimental group consisted of five healthy volunteers who received phylloquinone after an overnight fast. on the first day of three successive weeks the participants consumed 1 mg (2 ...	1996	8813897
c-terminal truncation of spinach chloroplast nad(p)-dependent glyceraldehyde-3-phosphate dehydrogenase prevents inactivation and reaggregation.	chloroplast nad(p)-dependent glyceraldehyde-3-phosphate dehydrogenase (nad(p)-gapdh; ec 1.2.1.13) consists of two types of subunits: gapa and gapb, which are rather similar, except that gapb carries an unique c-terminal sequence extension. here, we report evidence that this sequence extension might be responsible for aggregation and dark inactivation of the enzyme in vivo. recently, it had been demonstrated that upon limited proteolysis of the purified 600 kda enzyme, using the staphylococcus au ...	1996	8814230
comparison of the "rieske" [2fe-2s] center in the bc1 complex and in bacterial dioxygenases by circular dichroism spectroscopy and cyclic voltammetry.	two different types of "rieske" [2fe-2s] clusters have been observed in proteins, one in the bc complexes of the respiratory chain and the other in bacterial dioxygenases. we have compared the circular dichroic (cd) spectra and redox properties of the water soluble fragment of the rieske center of the bovine heart mitochondrial bc1 complex (isf) and of the ferredoxin from benzene dioxygenase in pseudomonas putida ml2 (fdbed). spinach ferredoxin was also measured for comparison. the redox potenti ...	1996	8652534
nutritional support to prevent and treat multiple organ failure.	enteral nutrition (en) has several advantages over parenteral nutrition (pn) for postoperative/posttrauma patients. modern technologies for tube-feeding have made early en possible. jejunal tube-feeding has advantages over gastric tube-feeding: faster metabolic recovery, less vomiting, and less risk of regurgitation and aspiration. immediate or early en stimulates the splanchnic and hepatic circulations, improves mucosal blood flow, prevents intramucosal acidosis and permeability disturbances, a ...	1996	8662138
comparative immunological detection of lipids and carotenoids on peptides of photosystem i from higher plants and cyanobacteria.	photosystem i preparations were obtained from wild-type tobacco nicotiana tabacum var. jwb, three chlorophyll-deficient tobacco mutants: su/su, su/su var. aurea and yellow-green leaf patches of the variegated mutant nc 95, spinacia oleracea and furthermore from the mesophilic cyanobacterium synechococcus pcc 7942 and the thermophilic cyanobacterium synechococcus sp.. peptides from these preparations were analyzed by sds polyacrylamide gel electrophoresis and transferred for detection of bound li ...	1996	8663897
pigment quantitation and analysis by hplc reverse phase chromatography: a characterization of antenna size in oxygen-evolving photosystem ii preparations from cyanobacteria and plants.	photosystem ii, the photosynthetic water-oxidizing complex, can be isolated from both plants and cyanobacteria. a variety of methods have been developed for purification of this enzyme, which can be isolated in several functional and structural forms. knowledge of the pigment content of photosystem ii preparations is important for precise spectroscopic, biochemical, and functional analysis. we have determined pigment stoichiometries in oxygen-evolving photosystem ii preparations from plants and ...	1996	8672481
the redox potentials of flavodoxin from desulfovibrio vulgaris and ferredoxin-nadp+ reductase from spinacia oleracea and their complexes.		1996	8674686
effects of irrelevant sounds on phonological coding in reading comprehension and short-term memory.	the effects of irrelevant sounds on reading comprehension and short-term memory were studied in two experiments. in experiment 1, adults judged the acceptability of written sentences during irrelevant speech, accompanied and unaccompanied singing, instrumental music, and in silence. sentences varied in syntactic complexity: simple sentences contained a right-branching relative clause (the applause pleased the woman that gave the speech) and syntactically complex sentences included a centre-embed ...	1996	8685391
the conformation of the isoprenyl chain relative to the semiquinone head in the primary electron acceptor (qa) of higher plant psii (plastosemiquinone) differs from that in bacterial reaction centers (ubisemiquinone or menasemiquinone) by ca. 90 degrees.	the conformation and partial electron spin density distribution of the reduced primary electron acceptor (qa-), a plastosemiquinone-9 (pq-9-) anion radical, in photosystem ii protein complexes from spinach as well as free pq-9- in solution have been determined by epr and 1h endor spectroscopies. the data show that the conformation of the isoprenyl chain at c beta relative to the aromatic ring differs by 90 degrees for qa- in higher plant psii versus both types of bacterial reaction centers, rhod ...	1996	8688432
metal binding sites of h(+)-atpase from chloroplast and bacillus ps3 studied by epr and pulsed epr spectroscopy of bound manganese(ii).	the metal binding sites of isolated f1 atpase from spinach chloroplasts (cf1) and from the thermophilic bacterium bacillus ps3 (tf1) have been studied by epr and pulsed epr spectroscopy using mn(ii) as a paramagnetic probe. after dialysis in the presence of edta, purified cf1 retains 0.14 +/- 0.07 mg(ii) and approximately 0.75 +/- 0.25 adp. tf1 retains 0.31 +/- 0.03 mg(ii) and 0.08 +/- 0.01 nucleotide (adp + atp) after the same treatment. supplementing known quantities of mn(ii) to metal-deplete ...	1996	8703962
evidence for the expression of the triosephosphate translocator gene in green and non-green tissue of tomato and potato.	western blot analysis revealed a cross reaction of an antibody against the spinach triosephosphate translocator with 29 kda proteins from envelope membranes of plastids from green and red tomato fruits and also of potato tuber amyloplasts. envelope membranes from potato tubers were isolated from a homogenate of total membranes by isopycnic sucrose density gradient centrifugation. we were able to demonstrate by reverse transcription and sequencing of the pcr product that the mrna for the trioseph ...	1996	8704143
major fruit and vegetable contributors to the main serum carotenoids in the spanish diet.	to identify the main sources of serum carotenoids (lutein, zeaxanthin, lycopene, beta-cryptoxanthin, alpha-carotene and beta-carotene) among the fruits and vegetables in the spanish diet, to be used in the design of food questionnaires and to provide useful information for epidemiological and comparative studies.	1996	8730612
molecular cloning and photoperiod-regulated expression of gibberellin 20-oxidase from the long-day plant spinach.	spinach (spinacia oleracea l.) is a long-day (ld) rosette plant in which stem growth under ld conditions is mediated by gibberellins (gas). major control points in spinach are the later steps of sequential oxidation and elimination of c-20 of c20-gas. degenerate oligonucleotide primers were used to obtain a polymerase chain reaction product from spinach genomic dna that has a high homology with ga 20-oxidase cdnas from cucurbita maxima l. and arabidopsis thaliana heynh. this polymerase chain rea ...	1996	8742334
carboxyl-terminal processing protease for the d1 precursor protein: cloning and sequencing of the spinach cdna.	a previous study has demonstrated that the carboxyl-terminal (c-terminal) processing protease in spinach for the d1 precursor protein (pdl) of the photosystem ii reaction center is a monomeric protein of about 45 kda. based on the amino acid sequence data of the purified protease, a cdna clone encoding the enzyme has been identified and sequenced, from a spinach green leaf cdna library. in order to determine the 5' end of the transcript, the rapid amplification of cdna end (5'-race) technique wa ...	1996	8616242
spinach chloroplast 0-acetylserine (thiol)-lyase exhibits two catalytically non-equivalent pyridoxal-5'-phosphate-containing active sites.	a synthetic gene encoding the mature spinach- chloroplast o-acetylserine (thiol)-lyase was constructed and expressed in an escherichia coli strain carrying the t7 rna polymerase system. the pure recombinant protein was obtained at high yield (6 mg/l cell culture) using a new purification procedure that includes affinity chromatography on green a agarose. its specific activity was of the order of 1000 u/mg, and its physical properties were similar to those previously reported for the natural enzy ...	1996	8617276
cdnas encoding spinach stromal and thylakoid-bound ascorbate peroxidase, differing in the presence or absence of their 3'-coding regions.	two cdna clones encoding stromal (sap28) and thylakoid-bound (sap22) ascorbate peroxidase were isolated from a spinach cdna library constructed by greening cotyledons. the sap22 and sap28 contained an open reading frame encoding mature protein of 295 and 345 amino acids with calculated molecular mass of 32239 da and 37710 da, respectively, preceded by the common transit peptides of 70 amino acid residues. interestingly, the n-terminal 364 amino acids of sap22 were 100% identical with sap28 excep ...	1996	8617374
monitoring of pesticide residues in human milk, soil, water, and food samples collected from kafr el-zayat governorate.	pesticide residues in human milk and environmental samples from kafr el-zayat governorate in egypt were analyzed. this governorate is located near one of the biggest pesticide factories in egypt. organochlorine and organophosphorus pesticides were monitored, including those that have been prohibited from use in egypt. human milk samples (31 samples) from kafr el-zayat were compared with 11 samples collected from cairo. data were compared with results from studies performed in 1987 and 1990. the ...	1996	8620102
efficient expression of the gene for spinach phosphoribulokinase in pichia pastoris and utilization of the recombinant enzyme to explore the role of regulatory cysteinyl residues by site-directed mutagenesis.	phosphoribulokinase (prk), unique to photosynthetic organisms, is regulated in higher plants by thioredoxin-mediated thiol-disulfide exchange in a light-dependent manner. prior attempts to overexpress the higher plant prk gene in escherichia coli for structure-function studies have been hampered by sensitivity of the recombinant protein to proteolysis as well as toxic effects of the protein on the host. to overcome these impediments, we have spliced the spinach prk coding sequence immediately do ...	1996	8626451
plant calreticulin is specifically and efficiently phosphorylated by protein kinase ck2.	calreticulin isolated from spinach leaves has been specifically phosphorylated in vitro by protein kinase ck2 while animal calreticulin from rabbit liver is not a substrate of this kinase under the same conditions. phosphoserine is the only phosphoamino acid detected. high affinity binding (km = 4.4 microm) and a nearly stoichiometric incorporation of phosphate was determined. partially purified spinach calreticulin is phosphorylated at the same site(s) by a copurifying protein kinase sharing bi ...	1996	8629990
endor and special triple resonance spectroscopy of a1.- of photosystem 1.	the photoaccumulated radical state of the photosystem 1 secondary electron acceptor a1, a1.-, has been studied in spinach and the cyanobacterium anabaena variabilis strain met27 using electron nuclear double resonance (endor) and electron--nuclear--nuclear special triple (st) resonance spectroscopies. spectra of a1.- in both these species are very similar. endor spectra of the phylloquinone anion radical in solvent glass were also obtained. comparison of the spectra of the in vivo and in vitro r ...	1996	8639614
binding site on pea chloroplast fructose-1,6-bisphosphatase involved in the interaction with thioredoxin.	when we compare the primary structures of the six chloroplast fructose-1,6-biophosphatases (fbpase) so far sequenced, the existence of a poorly conserved fragment in the region just preceeding the redox regulatory cysteines cluster can be observed. this region is a good candidate for binding of fbpase to its physiological modulator thioredoxin (td), as this association shows clear differences between species. using a cdna clone for pea chloroplast fbpase as template, we have amplified by pcr a d ...	1996	8605298
occurrence of silent rna editing in chloroplasts: its species specificity and the influence of environmental and developmental conditions.	we have identified three new c-to-u rna editing sites, one in atpf and two in atpa transcripts from tobacco chloroplasts. two of them lead to amino acid substitutions to restore the conserved amino acid found in the corresponding genes of other plants. however, one editing site in the atpa transcript was found to take place partially at the third base of a serine codon (cuc_ to cuu_), thus not leading to an amino acid substitution. this is the first report of silent editing in chloroplasts. the ...	1996	8605316
distribution of thiols in microorganisms: mycothiol is a major thiol in most actinomycetes.	mycothiol [2-(n-acetylcysteinyl)amido-2-deoxy-alpha-d-glucopyranosyl- (1-->1)-myo-inositol] (msh) has recently been identified as a major thiol in a number of actinomycetes (s. sakuda, z.-y. zhou, and y. yamada, biosci. biotech. biochem. 58:1347-1348, 1994; h. s. c. spies and d. j. steenkamp, eur. j. biochem. 224:203-213, 1994; and g. l. newton, c. a. bewley, t. j. dwyer, r. horn, y. aharonowitz, g. cohen, j. davies, d. j. faulkner, and r. c. fahey, eur. j. biochem. 230:821-825, 1995). since thi ...	1996	8606174
subcellular localization of spinach cysteine synthase isoforms and regulation of their gene expression by nitrogen and sulfur.	subcellular localization and regulation of the spinach (spinacia oleracea) cysteine synthase (o-acetyl-l-serine[thiol]-lyase, ec 4.2.99.8) isoforms (cysa, cysb, and cysc) were determined in transgenic tobacco (nicotiana tabacum) and in spinach cell cultures. the 5' regions of cysb and cysc encoding the chloroplastic (cysb-tp) and the putative mitochondrial (cysc-tp) transit peptide (tp) sequences were fused to a bacterial beta-glucuronidase gene (gus) and expressed in tobacco under the control o ...	1996	8819326
interspecies cross-reactivity of a monoclonal antibody directed against wheat chloroplast fructose-1,6-bisphosphatase.	the primary structure of several chloroplast fructose-1,6-bisphosphatase (cfbpase) was deduced from dna sequences, but only spinach, pea and rapeseed enzymes have been characterized structurally. we analyzed whether cfbpases from different phylogenetic origin contain a common epitope. to this end a dna fragment of 1200 base pairs encoding 338 amino acid residues of wheat cfbpase (38 kda) was cloned in the expression plasmid pgex-1 in frame with the gene coding for glutathione s-transferase (gt) ...	1996	8832098
cloning and molecular analysis of cdnas encoding three sucrose phosphate synthase isoforms from a citrus fruit (citrus unshiu marc.).	three partial cdna clones (psps1, psps2 and psps3) encoding sucrose phosphate synthases (sps) were isolated by reverse transcription (rt)-pcr using first-strand cdna prepared from the leaf or fruit of citrus (citrus unshiu marc.). the nucleotide and deduced amino acid sequences of the three clones showed significant similarities to sps previously isolated in other plants. a full-length, cdna clone, citsps1, was isolated from a fruit (juice sacs and pulp segment) cdna library using one (psps1) of ...	1996	8842155
kinetic evidence for protein complexes between thioredoxin and nadp-malate dehydrogenase and presence of a thioredoxin binding site at the n-terminus of the enzyme.	the kinetics of activation of nadp-malate dehydrogenase (mdh; ec 1.1.1.82) from soybean and spinach leaves by the chloroplast thioredoxins isolated from the same plants, by the corresponding storage forms of the soybean chloroplast thioredoxins from soybean seeds, and by the bacterial escherichia coli thioredoxin have been studied. the hill equation has been applied to evaluate the saturation kinetics. the observed variable thioredoxin saturation characteristics (vmax 0.37-14.5 mumol nadph min-1 ...	1996	8856084
some characteristics of cytochrome f in the cyanobacterium phormidium laminosum: its sequence and charge properties in the reaction with plastocyanin.	part of the petca operon was cloned and the sequence of the cytochrome f gene from the moderately thermophilic cyanobacterium phormidium laminosum determined. a partial sequence of the petc gene encoding the rieske iron-sulphur protein was also obtained. the cytochrome f gene encodes a mature protein of 385 residues and a leader sequence of 45 residues. the mature protein contains several acidic or neutral residues corresponding to basic residues in the turnip protein. some of the latter are tho ...	1996	8856106
changes in microbial populations on fresh cut spinach.	the microbial populations found on fresh-cut spinach leaves that were stored in gas permeable bags at 10 degrees c for 12 days were examined and identified. the microorganisms consisted of mesophilic aerobic bacteria, psychrotrophic bacteria, pseudomonadaceae, enterobacteriaceae, micrococcaceae, lactic acid bacteria and yeasts. populations of mesophiles, psychrotrophs, pseudomonadaceae and enterobacteriaceae increased sharply during the storage period. the initial populations were 10(7), 10(6), ...	1996	8880301
x-ray structure of the ferredoxin:nadp+ reductase from the cyanobacterium anabaena pcc 7119 at 1.8 a resolution, and crystallographic studies of nadp+ binding at 2.25 a resolution.	the crystal structure of the ferredoxin:nadp+ reductase (fnr) from the cyanobacterium anabaena pcc 7119 has been determined at 2.6 a resolution by multiple isomorphous replacement and refined using 15.0 a to 1.8 a data, collected at 4 degrees c, to an r-factor of 0.172. the model includes 303 residues, the flavin adenine dinucleotide cofactor (fad), one sulfate ion located at the putative nadp+ binding site and 328 water molecule sites. the structure of anabaena fnr, including fad, a network of ...	1996	8890910
introduction and expression of foreign dna in isolated spinach chloroplasts by electroporation.	an electroporation-mediated method for the study of foreign gene expression within chloroplasts has been developed. the chloroplast expression vector phd203-gus, which consists of coding regions for beta-glucuronidase (gus) and chloramphenicol acetyltransferase (cat) separated by a double psba promoter fragment from pea (in opposite orientation) was electroporated into spinach chloroplasts and the transient gene expression was examined. conditions for the expression of the reporter genes have be ...	1996	8893549
amino acid sequence of the maize ferredoxin:thioredoxin reductase variable subunit.	the ferredoxin:thioredoxin reductase (ftr) is the essential enzyme of the light dependent regulatory system controlling enzyme activities in oxygenic, photosynthetic cells. this protein is composed of two dissimilar subunits, a catalytic subunit containing a [4fe-4s] cluster and a redox-active disulfide bridge as the active site, and a variable subunit, whose function is not known yet. whereas size and primary structure of the catalytic subunit from different organisms seem to be well conserved, ...	1996	8898896
purification and partial characterization of two thioredoxins from streptomyces aureofaciens.	thioredoxins are low molecular weight proteins, which participate in a wide spectrum of biochemical reactions. two thioredoxins from streptomyces aureofaciens 3239 have been purified to homogeneity by a sequence of chromatography steps including chromatography on sephacryl s-300, phenyl sepharose cl 4b and monoq hr 5/5. thioredoxin activity clearly separates into two protein fractions on monoq hr 5/5 chromatography. molecular weights determined by chromatography on superose 12 hr 10/30 and sodiu ...	1996	8908358
identification, characterization, and molecular cloning of a homologue of the bacterial ftsh protease in chloroplasts of higher plants.	in an attempt to identify and characterize chloroplast proteases, we performed an immunological analysis of chloroplasts using an antibody against escherichia coli ftsh protease, which is an atp-dependent metalloprotease bound to the cytoplasmic membrane. a cross-reacting protein of 78 kda was found in the thylakoid membrane of spinach, but not in the soluble stromal fraction. alkali and high salt washes, as well as trypsin treatment of thylakoid membranes, suggest that the chloroplastic ftsh pr ...	1996	8910594
evidence that the plastid signal and light operate via the same cis-acting elements in the promoters of nuclear genes for plastid proteins.	nuclear-encoded genes for proteins of the photosynthetic machinery represent a particular subset of genes. their expression is cooperatively stimulated by discrete factors including the developmental stage of plastids and light. we have analyzed in transgenic tobacco the plastid- and light-dependent expression of a series of 5' promoter deletions of various nuclear genes from spinach, of fusions of defined promoter segments with the 90-bp 35s rna camv minimal promoter, as well as with mutations ...	1996	8917305
stability of food allergens to digestion in vitro.	an integral part of the safety assessment of genetically modified plants is consideration of possible human health effects, especially food allergy. prospective testing for allergenicity of proteins obtained from sources with no prior history of causing allergy has been difficult because of the absence of valid methods and models. food allergens may share physicochemical properties that distinguish them from nonallergens, properties that may be used as a tool to predict the inherent allergenicit ...	1996	9631091
cucumber chloroplast trnl(caa) gene: nucleotide sequence and in vivo expression analysis in etiolated cucumber seedlings treated with benzyladenine and light.	the nucleotide sequence of a 714 bp bamhi-ecori fragment of cucumber chloroplast dna was determined. the fragment contained a gene for trna(leu) together with its flanking regions. the trnl(caa) gene sequence is about 99% in similarity to broad bean, cauliflower, maize, spinach and tobacco corresponding genes. the relative expression level of the gene was determined by northern (trna) gel blot and northern (total cellular rna) slot-blot analyses using the trnl gene probe in 6-day old etiolated c ...	1996	9219428
the chloroplast envelope is permeable for maltose but not for maltodextrins.	permeation of [14 c]maltose into the stroma (measured as the sorbitol-impermeable space) of isolated intact spinach (spinacia oleracea l.) chloroplasts was studied using the silicone oil centrifugation technique. maltose uptake showed michaelis menten-kinetics with a k(m) of 25 mm and a vmax of 19.5 mumol maltose. mg chl-1. h-1 at 15 degrees c. lack of interaction of glucose and maltose uptake suggested the presence of individual translocators for maltose and glucose in the inner chloroplast env ...	1996	8980636
greenhouse spinach production in a nft system.	primed spinach (spinacia oleracea l., cv. nordic) seed was started in rockwool slabs in a growth room for eight days before the seedlings were transplanted into a controlled environment greenhouse equipped with five identical, but separate, nft systems. the day and night temperatures in the greenhouse were maintained at 24 and 18 degrees c, respectively, with the daytime starting at 06:00 and ending at 22:00 hr. a photoperiod of 16 hrs was maintained, to prevent early bolting, and different targ ...	1996	11541569
primary structure of the n-linked carbohydrate chains of calreticulin from spinach leaves.	calreticulin is a multifunctional ca(2+)-binding protein of the endoplasmic reticulum of most eukaryotic cells. the 56 kda calreticulin glycoprotein isolated from spinach (spinacia oleracea l.) leaves was n-deglycosylated by pngase-f digestion. the carbohydrate moiety was isolated by gel permeation chromatography and purified by high-ph anion-exchange chromatography. the fractions were investigated by 500 mhz 1h-nmr spectroscopy, in combination with monosaccharide analysis and fast-atom bombardm ...	1996	8981089
carbohydrate and carbon metabolite accumulation responses in leaves of ozone tolerant and ozone susceptible spinach plants after acute ozone exposure.	the objective of this study was to determine whether exposure of plants to ozone (o3) increased the foliar levels of glucose, glucose sources, e.g., sucrose and starch, and glucose-6-phosphate (g6p), because in leaf cells, glucose is the precursor of the antioxidant, l-ascorbate, and glucose-6-phosphate is a source of nadph needed to support antioxidant capacity. a further objective was to establish whether the response of increased levels of glucose, sucrose, starch and g6p in leaves could be c ...	1996	24271929
higher-plant chloroplast and cytosolic fructose-1,6-bisphosphatase isoenzymes: origins via duplication rather than prokaryote-eukaryote divergence.	full-size cdnas encoding the precursors of chloroplast fructose-1,6-bisphosphatase (fbp), sedoheptulose-1,7-bisphosphatase (sbp), and the small subunit of rubisco (rbcs) from spinach were cloned. these cdnas complete the set of homologous probes for all nuclear-encoded enzymes of the calvin cycle from spinach (spinacia oleracea l.). fbp enzymes not only of higher plants but also of non-photosynthetic eukaryotes are found to be unexpectedly similar to eubacterial homologues, suggesting a eubacter ...	1996	8980497
nearest-neighbor analysis of higher-plant photosystem i holocomplex.	photosystem 1 (psi) preparations from barley (hordeum vulgare) and spinach (spinacia oleracea) were subjected to chemical cross-linking using the cleavable homobifunctional cross-linkers dithiobis(succinimidylpropionate) and 3,3'-dithiobis(sulfosuccinimidyl-propionate). the overall pattern of cross-linked products was analyzed by the simple but powerful technique of diagonal electrophoresis, in which the disulfide bond in the cross-linker was cleaved between the first and second dimensions of th ...	1996	8819335
purification and identification of the violaxanthin deepoxidase as a 43 kda protein.	violaxanthin deepoxidase (vde) has been purified from spinach (spinacia oleracea) leaves. the purification included differential sonication of thylakoid membranes, differential (nh4)2so4 fractionation, gel filtration chromatography and finally either hydrophobic interaction chromatography or anion exchange chromatography. a total purification of more than 5000-fold compared to the original thylakoids enabled the identification of a 43 kda protein as the vde, in contrast to earlier reported molec ...	1996	24271609
ion channel permeable for divalent and monovalent cations in native spinach thylakoid membranes.	a cation-selective channel was characterized in isolated patches from osmotically swollen thylakoids of spinach (spinacea oleracea). this channel was permeable for k+ as well as for mg2+ and ca2+ but not for cl-. when k+ was the main permeant ion (symmetrical 105 mm kcl) the conductance of the channel was about 60 ps. the single channel conductance for different cations followed a sequence k+ > mg2+ >/= ca2+. the permeabilities determined by reversal potential measurements were comparable for k+ ...	1996	8672080
the inhibitor protein of phosphorylated nitrate reductase from spinach (spinacia oleracea) leaves is a 14-3-3 protein.	the inhibitor protein (ip) that inactivates spinach leaf nadh:nitrate reductase (nr) has been identified for the first time as a member of the eukaryotic 14-3-3 protein family based on three lines of evidence. first, the sequence of an eight amino acid tryptic peptide, obtained from immunopurified ip, matched that of a highly conserved region of the 14-3-3 proteins. second, an authentic member of the 14-3-3 family, recombinant arabidopsis gf14omega, caused inactivation of phospho-nr in a magnesi ...	1996	8674533
characterization of the bifunctional mitochondrial processing peptidase (mpp)/bc1 complex in spinacia oleracea.	the mitochondrial general processing peptidase (mpp) in plant mitochondria constitutes an integral part of the cytochrome bc1 complex of the respiratory chain. here we present a characterization of this bifunctional complex from spinach leaf mitochondria. the purified mpp/bc1 complex has a molecular mass of 550 kda, which corresponds to a dimer. increased ionic strength results in partial dissociation of the dimer as well as loss of the processing activity. micellar concentrations of nonionic an ...	1996	8807403
primary structure and expression of plant homologues of animal and fungal thioredoxin-dependent peroxide reductases and bacterial alkyl hydroperoxide reductases.	higher plants express genes encoding peroxiredoxins of the two-cysteine type. this is concluded from the isolation of cdnas from spinach (spinacia oleracea) and barley (hordeum vulgare cv. gerbel) which are homologous to animal, fungal, and bacterial two-cysteine peroxiredoxins. northern blot analysis indicated the presence of at least one corresponding gene in all angiosperms analyzed suggesting that bas1 is a member of an ubiquitous gene family encoding a protein of fundamental importance in o ...	1996	8790288
evidence that isolated chloroplasts contain an integrated lipid-synthesizing assembly that channels acetate into long-chain fatty acids.	high rates of light-dependent fatty acid synthesis from acetate were measured in isolated chloroplasts that were permeabilized to varying extents by resuspension in hypotonic reaction medium. the reactions in hypotonic medium unsupplemented with cofactors were linear with time and were directly proportional to chlorophyll concentration, suggesting that the enzymes and cofactors of fatty acid synthesis remained tightly integrated and thylakoid associated within disrupted chloroplasts. permeabiliz ...	1996	12226255
envelope membranes from spinach chloroplasts are a site of metabolism of fatty acid hydroperoxides.	enzymes in envelope membranes from spinach (spinacia oleracea l.) chloroplasts were found to catalyze the rapid breakdown of fatty acid hydroperoxides. in contrast, no such activities were detected in the stroma or in thylakoids. in preparations of envelope membranes, 9s-hydroperoxy-10(e),12(z)-octadecadienoic acid, 13s-hydroperoxy-9(z),11(e)-octadecadienoic acid, or 13s-hydroperoxy-9(z),11(e),15(z)-octadecatrienoic acid were transformed at almost the same rates (1-2 [mu]mol min-1 mg-1 protein). ...	1996	12226196
guanosine triphosphate-binding proteins on the plasmalemma of spinach leaf cells.	the molecular mechanism of light perception through phytochrome is not well understood. this red-light photosensor has been implicated in various physiological processes, including the photoinduction of flowering. a few recent studies have shown that phytochrome initiates signal transduction chains via guanosine triphosphate (gtp)-binding proteins (g-proteins). we show here by different approaches that g-proteins exist in spinach (spinacia oleracea l. cv. nobel). binding of gtp on the plasmalemm ...	1996	28321666
purification and characterization of a cryoprotective protein (cryoprotectin) from the leaves of cold-acclimated cabbage.	we have purified a protein (cryoprotectin) from the leaves of cold-acclimated cabbage (brassica oleracea l.) that protects thylakoids from nonacclimated spinach (spinacia oleracea l.) against freeze-thaw damage. the procedure involves precipitations by heat, ammonium sulfate, and the glycosaminoglycan heparin and column chromatography on polyamide 6 and a c18 reverse-phase matrix. after reverse-phase chromatography we obtained a single band of an apparent molecular mass of 7 kd when fractions th ...	1996	12226287
unidirectional transport of orthophosphate across the envelope of isolated cauliflower-bud amyloplasts.	isolated amyloplasts from cauliflower (brassica oleracea l. var botrytis) buds are able to export orthophosphate unidirectionally into the incubation medium. this orthophosphate transport appears to be protein-mediated, as indicated by the following observations: (i) low temperature and the presence of inhibitors of protein-mediated transport reduced the rate of orthophosphate export, and (ii) the rate of orthophosphate export became saturated with rising internal substrate concentrations. micro ...	1996	28321664
chimaeric cp47 mutants of the cyanobacterium synechocystis sp. pcc 6803 carrying spinach sequences: construction and function.	chimaeric mutants of the cyanobacterium synechocystis sp. pcc 6803 have been generated carrying part or all of the spinach psbb gene, encoding cp47 (one of the chlorophyll-binding core antenna proteins in photosystem ii). the mutant in which the entire psbb gene had been replaced by the homologous gene from spinach was an obligate photoheterotroph and lacked photosystem ii complexes in its thylakoid membranes. however, this strain could be transformed with plasmids carrying selected regions of s ...	1996	24271295
photoinhibition of photosystem i electron transfer activity in isolated photosystem i preparations with different chlorophyll contents.	photoinhibition of the light-induced photosystem i (ps i) electron transfer activity from the reduced dichlorophenol indophenol to methyl viologen was studied. ps i preparations with chl/p700 ratios of about 180 (ps i-180), 100 (ps i-100) and 40 (ps i(ha)-40) were isolated from spinach thylakoid membranes by the treatments with triton x-100, followed by sucrose density gradient centrifugation and hydroxylapatite column chromatography. white light irradiation (1.1 × 10(4)μe m(-2) s(-1)) of ps i-1 ...	1996	24301820
[a survey of radioactive levels of agricultural products in saitama prefecture].	past atmospheric nuclear testing which have been conducted frequently, have caused environmental pollution due to the diffusion of radioactive substances into the atmosphere and from the radioactive fallout. the environmental pollution from nuclear testing into the atmosphere has resulted in the radioactive contamination in agricultural products and has continued for a long time. the radioactive contamination of agricultural products occurs through air, water and soil which were contaminated by ...	1997	9423326
molecular cloning and characterization of a cdna encoding putative phospholipid hydroperoxide glutathione peroxidase from spinach.	a cdna encoding spinach putative phospholipid hydroperoxide glutathione peroxidase (phgpx) was cloned and sequenced. the cdna included an open reading frame that encoded a polypeptide of 171 amino acid residues. the deduced amino acid sequence showed about 77 and 50% similarity to plant putative phgpxs and mammalian phgpxs, respectively. pcr product with the same size as that of the spinach putative phgpx were obtained from maize, soybeans, and arabidopsis, suggesting the expression of putative ...	1997	9301122
physical and kinetic evidence for an association between sucrose-phosphate synthase and sucrose-phosphate phosphatase.	the possible formation of a multienzyme complex between sucrose (suc)-phosphate synthase (sps) and suc-phosphate phosphatase (spp) was examined by measuring the rates of suc-6-phosphate (suc-6-p) synthesis and hydrolysis in mixing experiments with partially purified enzymes from spinach (spinacia oleracea) and rice (oryza sativa) leaves. the addition of spp to sps stimulated the rate of suc-6-p synthesis. sps inhibited the hydrolysis of exogenous suc-6-p by spp when added in the absence of its s ...	1997	12223802
[nutrient content in vegetable species from the argentine chaco].	the nutrient composition was investigated in wild vegetable products grown in the argentine chaco. the evaluated species were: rumex sp., amaranthus quitensis and taraxacum officinale, as vegetable leaves; morrenia odorata, passiflora sp. (in two ripening stages) and eugenia myrciantes as fruits; and the pollen of the flowers of typha domingensis. sampling was performed during three harvesting seasons. values for protein, total lipid, crude fiber, ash, reducing and total sugar, starch, total pec ...	1997	9673684
alternative mrna splicing of 3'-terminal exons generates ascorbate peroxidase isoenzymes in spinach (spinacia oleracea) chloroplasts.	we have isolated two cdna clones encoding spinach (spinacia oleracea) stromal and thylakoid-bound ascorbate peroxidase isoenzymes [ishikawa, sakai, yoshimura, takeda and shigeoka (1996) febs lett. 384, 289-293]. the gene (apxii) encoding both chloroplastic ascorbate peroxidase isoenzymes was isolated and the organization of the gene was determined. alignment between the cdnas and the gene for chloroplastic ascorbate peroxidase isoenzymes indicates that both enzymes arise from a common pre-mrna b ...	1997	9396722
characterization of nitrate reductase from light- and dark-exposed leaves (comparison of different species and effects of 14-3-3 inhibitor proteins).	nitrate reductase (nr) was extracted and partially purified from leaves of squash (curcurbita maxima), spinach (spinacia oleracea), and three transgenic nicotiana plumbaginifolia leaves in the presence of phosphatase inhibitors to preserve its phosphorylation state. purified squash nr showed activation by substrates (hysteresis) when prepared from leaves in the light as well as in darkness. a 14-3-3 protein known to inhibit phosphorylated spinach nr in the presence of mg2+ decreased by 70 to 85% ...	1997	12223776
three spinach leaf nitrate reductase-3-hydroxy-3-methylglutaryl-coa reductase kinases that are regulated by reversible phosphorylation and/or ca2+ ions.	in spinach (spinacea oleracea l.) leaf extracts, three protein kinases (pki, pkii and pkiii) were identified each of which phosphorylated spinach nitrate reductase on serine-543, and inactivated the enzyme in the presence of nitrate reductase inhibitor, 14-3-3. pkiii was also very active in phosphorylating and inactivating arabidopsis (landsberg erecta) 3-hydroxy-3-methylglutaryl-coenzyme a reductase 1 (hmgr1). pki and pkii phosphorylated hmgr1 more slowly than pkiii, compared with their relativ ...	1997	9245257
the ferredoxin-binding site of ferredoxin: nitrite oxidoreductase. differential chemical modification of the free enzyme and its complex with ferredoxin.	spinach (spinacea oleracea) leaf ferredoxin (fd)-dependent nitrite reductase was treated with either the arginine-modifying reagent phenyl-glyoxal or the lysine-modifying reagent pyridoxal-5'-phosphate under conditions where only the fd-binding affinity of the enzyme was affected and where complex formation between fd and the enzyme prevented the inhibition by either reagent. modification with [14c]phenylglyoxal allowed the identification of two nitrite reductase arginines, r375 and r556, that a ...	1997	9232882