Publications

laser flash photolysis studies of the kinetics of reduction of spinach and clostridium ferredoxins by a viologen analogue: electrostatically controlled nonproductive complex formation and differential reactivity among the iron-sulfur clusters.	we have studied the transient kinetics of electron transfer from a positively charged viologen analogue (propylene diquat), reduced by pulsed laser excitation of the deazariboflavin/edta system, to the net negatively charged ferredoxins from spinach and clostridium pasteurianum. spinach ferredoxin showed monophasic kinetics over the ionic strength range studied, consistent with the presence of only a single iron-sulfur center. clostridium ferredoxin at low ionic strength showed biphasic kinetics ...	1989	2775750
purification, characterization and revised amino acid sequence of a second thioredoxin from corynebacterium nephridii.	a second thioredoxin, distinct from the one reported by meng and hogenkamp in 1981 (j. biol. chem. 256, 9174-9182), has been purified to homogeneity from an escherichia coli strain containing a plasmid encoding a corynebacterium nephridii thioredoxin. thioredoxin genes from c. nephridii were cloned into the plasmid puc13 and transformants were identified by complementation of a thioredoxin negative (trxa-) e. coli strain. the abilities of the transformants to support the growth of several phages ...	1989	2917572
a 4-kda maize chloroplast polypeptide associated with the cytochrome b6-f complex: subunit 5, encoded by the chloroplast pete gene.	four polypeptides, three of which are chloroplast-encoded, have been shown to be associated with the thylakoid membrane cytochrome b6-f complex. in this report, the gene for a fifth polypeptide, which copurifies with the b6-f complex, is identified through the use of an antibody generated against a synthetic decapeptide predicted from a maize chloroplast dna sequence. the deduced 37-amino acid sequence of the immunoreactive 4-kda polypeptide is 100% and 86% conserved in the respective similar op ...	1989	2922397
selective inhibition of photosystem ii in spinach by tobacco mosaic virus: an effect of the viral coat protein.	leaves of spinacia oleracea inoculated with tobacco mosaic virus (tmv) strain pv230 develop mild chlorotic and mosaic symptoms of infection. thylakoid membranes isolated from these infected leaves showed a reduced fv/fm ratio for chlorophyll fluorescence kinetics, at 25 degrees c. the photosystem ii (ps ii)-mediated electron-transport rate was inhibited 50%, whereas ps i activity was unaffected by virus infection. protein analysis indicated that tmv coat protein was associated with thylakoids, i ...	1989	2924924
plant cells contain calsequestrin.	calsequestrin is a high capacity low affinity ca2+-binding protein thought to be essential for the function of the intracellular rapid releasable ca2+ pool of a variety of animal cells. here we show that two types of plant tissues, cultured streptanthus tortuosus cells and spinach leaves, contain a form of calsequestrin. in subcellular fractions of s. tortuosus cells, stains-all staining reveals a metachromatically blue-staining 56,000-da protein enriched in the microsomal fraction. this protein ...	1989	2925646
post-translational modifications in the large subunit of ribulose bisphosphate carboxylase/oxygenase.	two adjacent n-terminal tryptic peptides of the large subunit of ribulose bisphosphate carboxylase/oxygenase [3-phospho-d-glycerate carboxy-lyase (dimerizing), ec 4.1.1.39] from spinach, wheat, tobacco, and muskmelon were removed by limited tryptic proteolysis. characterization by peptide sequencing, amino acid composition, and tandem mass spectrometry revealed that the n-terminal residue from the large subunit of the enzyme from each plant species was acetylated proline. the sequence of the pen ...	1989	2928307
potential utilization of algal protein concentrate as a food ingredient in space habitats.	green alga scenedesmus obliquus was studied as one of the potential sources of macronutrients in a space habitat. algal protein concentrate (70.5% protein) was incorporated into a variety of food products such as bran muffins, fettuccine (spinach noodle imitation) and chocolate chip cookies. food products containing 20 to 40% of incorporated algal proteins were considered. in the sensory analysis the greenish color of the bran muffins and cookies was not found to be objectional. the mild spin ...	1989	11538068
spinach chloroplast rpobc genes encode three subunits of the chloroplast rna polymerase.	sequence analysis of a 12,400 base-pair region of the spinach chloroplast genome indicates the presence of three genes encoding subunits of the chloroplast rna polymerase. these genes are analogous to the rpobc operon of escherichia coli, with some significant differences. the first gene, termed rpob, encodes a 121,000 mr homologue of the bacterial beta subunit. the second and third genes, termed rpoc1 and rpoc2, encode 78,000 and 154,000 mr proteins homologous to the n and c-terminal portions, ...	1988	3045324
the protein responsible for center a/b in spinach photosystem i: isolation with iron-sulfur cluster(s) and complete sequence analysis.	the 9 kda polypeptide from spinach photosystem i (ps i) complex was isolated with iron-sulfur cluster(s) by an n-butanol extraction procedure under anaerobic conditions. the polypeptide was soluble in a saline solution and contained non-heme irons and inorganic sulfides. the absorption spectrum of this iron-sulfur protein was very similar to those of bacterial-type ferredoxins. the amino acid sequence of the polypeptide was determined by using a combination of gas-phase sequencer and conventiona ...	1988	3049567
chloroplast rpoa, rpob, and rpoc genes specify at least three components of a chloroplast dna-dependent rna polymerase active in trna and mrna transcription.	the purpose of this study was to determine the relationship between putative chloroplast rna polymerase subunit genes and known chloroplast transcriptional activities. we have prepared fusion polypeptide genes from fragments of chloroplast dna homologous to bacterial rna polymerase subunit genes and expression vectors carrying portions of the anthranilate synthetase gene (trpe). fusion proteins for chloroplast homologs of the rna polymerase alpha (rpoa), beta (rpob), and beta' (rpoc) subunits we ...	1988	3049574
a new photosystem ii reaction center component (4.8 kda protein) encoded by chloroplast genome.	the photosystem ii reaction center complex, so-called d1-d2-cytochrome b-559 complex, isolated from higher plants contains a new component of about 4.8 kda [(1988) plant cell physiol. 29, 1233-1239]. the partial amino acid sequence of this component from spinach was determined after release of n-terminal blockage. the determined sequence matched an open reading frame (orf36) of the chloroplast genome from tobacco and liverwort, which is located downstream from the psbk gene and forms an operon w ...	1988	3058517
rat kidney l-2-hydroxyacid oxidase. structural and mechanistic comparison with flavocytochrome b2 from baker's yeast.	hydroxyacid oxidase from rat kidney is an fmn-dependent enzyme that catalyzes the oxidation of l-alpha-hydroxy acids as well as, more slowly, that of l-alpha-amino acids. we report here a modified purification method for the enzyme, which is found to possess one cofactor per subunit of mr 39,000. determination of its n-terminal sequence suggests the protein is homologous to spinach glycolate oxidase and baker's yeast lactate dehydrogenase. in the presence of a hydroxy acid and of bromopyruvate, ...	1988	3061453
primary structure of barley genes encoding quinone and chlorophyll a binding proteins of photosystem ii.	the psba, psbd and psbc genes encoding the quinone binding d-1 and d-2 apoproteins and the 44 kd chlorophyll a-apoprotein 3 have been located in the chloroplast genome of barley. they are found on a 23 kbp sali restriction endonuclease fragment in the large single copy region of the chloroplast dna adjacent to the inverted repeat. as in other species the psbd and psbc genes have reading frames which overlap by 53 bp. they are transcribed in the same direction but translated with a frameshift of ...	1988	3076375
purification and properties of ferredoxin-nadp+ oxidoreductase from the nitrogen-fixing cyanobacteria anabaena variabilis.	the isolation and characterization of ferredoxin-nadp+ -oxidoreductase from anabaena variabilis, a nitrogen-fixing, filamentous cyanobacterium, is described. purified enzyme was obtained in four steps with a 55% yield and 300-fold purification utilizing chromatographic separations on deae-cellulose and cibacron blue-sepharose columns. the enzyme is quite similar but not identical to the spinach enzyme as judged by isoelectric focusing, molecular weight determination, and amino acid composition. ...	1988	3124746
adenylate cyclase activity in a higher plant, alfalfa (medicago sativa).	an adenylate cyclase activity in medicago sativa l. (alfalfa) roots was partially characterized. the enzyme activity remains in the supernatant fluid after centrifugation at 105,000 g and shows in crude extracts an apparent mr of about 84,000. the enzyme is active with mg2+ and ca2+ as bivalent cations, and is inhibited by egta and by chlorpromazine. calmodulin from bovine brain or spinach leaves activates this adenylate cyclase.	1988	3128270
algal heme oxygenase from cyanidium caldarium. partial purification and fractionation into three required protein components.	enzymatic heme oxygenase activity has been partially purified from extracts of the unicellular red alga cyanidium caldarium, and the macromolecular components have been separated into three protein fractions, referred to as fractions i, ii, and iii, by serial column chromatography through deae-cellulose and reactive blue 2-sepharose. fraction i is retained by deae-cellulose at low salt concentration and eluted by 1 m nacl. fraction ii is retained by blue sepharose at low salt concentration and e ...	1988	3136167
catalysis by cyanobacterial ribulose-bisphosphate carboxylase large subunits in the complete absence of small subunits.	an expression plasmid incorporating the structural gene for the large subunit of a cyanobacterial ribulose-bisphosphate carboxylase, but not the gene for its complementary small subunit, directs the synthesis of large subunits in escherichia coli. this provides a means for obtaining a preparation of large subunits completely devoid of small subunits, which is not otherwise achievable. in extracts, these large subunits were found predominantly in the form of octamers, but intersubunit interaction ...	1988	3137223
low-potential iron-sulfur centers in photosystem i: an x-ray absorption spectroscopy study.	we have measured the x-ray absorption spectra of fe in photosystem i (ps i) preparations from spinach and a thermophilic cyanobacterium, synechococcus sp., to characterize structures of the fe complexes that function as electron acceptors in ps i. these acceptors include centers a and b, which are probably typical [4fe-4s] ferredoxins, and x. the structure of x is not known, but its electron paramagnetic resonance (epr) spectrum has generated the suggestions that it is either a [2fe-2s] or [4fe- ...	1988	3137969
nucleotide sequence and transcript analysis of three photosystem ii genes from the cyanobacterium synechococcus sp. pcc7942.	the genome of the cyanobacterium synechococcus sp. pcc7942 contains two genes encoding the d2 polypeptide of photosystem ii (psii), which are designated here as psbdi and psbdii. the psbdi gene, like the psbd gene of plant chloroplasts, is cotranscribed with and overlaps the open reading frame of the psbc gene, encoding the psii protein cp43. the psbdii gene is not linked to psbc, and appears to be transcribed as a monocistronic message. the two psbd genes encode identical polypeptides of 352 am ...	1988	3138165
cloning, nucleotide sequence and mutational analysis of the gene encoding the photosystem ii manganese-stabilizing polypeptide of synechocystis 6803.	affinity purified, polyclonal antibodies raised against the photosystem ii 33 kda manganese-stabilizing polypeptide of the spinach oxygen-evolving complex were used to isolate the gene encoding the homologous protein from synechocystis 6803. comparison of the amino acid sequence deduced from the synechocystis psb1 nucleotide sequence with recently published sequences of spinach and pea confirms the homology indicated by antigenic cross-reactivity and shows that the cyanobacterial and higher plan ...	1988	3138527
characterization of a cyanobacterial iron stress-induced gene similar to psbc.	recently we have reported that the flavodoxin gene from the cyanobacterium anacystis nidulans r2 is transcribed as part of an iron stress-induced operon containing multiple mrna species (d. e. laudenbach, m. e. reith, and n. a. straus, j. bacteriol. 170: 258-265, 1988). here we report that nucleotide sequence analyses of dna located immediately upstream of the flavodoxin gene revealed an open reading frame of 1,026 bases (designated isia; iron stress inducible) with a deduced amino acid sequence ...	1988	3141374
structural determination of the photosystem ii core complex from spinach.	a photosystem ii core complex was purified with high yield from spinach by solubilization with beta-dodecylmaltoside. the complex consisted of polypeptides with molecular mass 47, 43, 34, 31, 9 and 4 kda and some minor components, as detected by silver-staining of polyacrylamide gels. there was no indication for the chlorophyll-a/b-binding, light-harvesting complex polypeptides. the core complex revealed electron-transfer activity (1,5-diphenylcarbazide----2,6-dichloroindophenol) of about 30 mum ...	1988	3144451
xenobiotic oxidation by cytochrome p-450-enriched extracts of streptomyces griseus.	crude extracts of streptomyces griseus grown on soybean flour-enriched medium contain high levels of cytochrome p-450. the cytochrome p-450-enriched fractions, obtained by ammonium sulfate fractionation (30-50% saturation), catalyze the nadph-dependent oxidation of a variety of xenobiotics when complemented with both spinach ferredoxin:nadp+ oxidoreductase and spinach ferredoxin. reactions observed are aromatic, benzylic and alicyclic hydroxylations, o-dealkylation, non-aromatic double bond epox ...	1988	3144975
evidence for a translation-mediated attenuation of a spinach chloroplast rdna operon.	the presence of potential hairpin structures h1, h2, h3 in the leader region of a spinach rdna operon led us to postulate that this operon is regulated by premature termination. the mechanism would be controlled by the presence or absence of ribosomes translating a leader peptide. in vitro synchronized transcription by e. coli rna polymerase shows that pauses do occur in the leader region. by their sizes, the transient transcripts could correspond to pauses on h1 and h2 as predicted by the model ...	1988	3148321
nucleotide sequence of maize chloroplast rps11 with conserved amino acid sequence between eukaryotes, bacteria and plastids.	nucleotide sequence of a 721 base pair segment of maize chloroplast dna, encoding the putative chloroplast ribosomal protein s11 at physical map position 33.1-33.5 kbp, is described. a shine-dalgarno sequence and computer-derived stem-loop structures of dyad symmetry are present in the spacer region between rps11 and its 5' upstream gene rpl36. the deduced amino acid sequence of maize chloroplast s11 shows 69%, 66%, 62%, 57%, 48% and 45% sequence identity to the corresponding sequences of tobacc ...	1988	3149198
cariogenicity of traditional african foodstuffs (maize, beans, sorghum, brown bread) on rat caries.	the cariogenicity of the following traditional african foods was tested in a rat model system: cooked maize and beans, cooked maize and spinach, uncooked and cooked sorghum, both plus 20% sucrose and brown bread, as well as a control (wheat starch plus 50% sucrose). plaque extent was low in all the test groups and caries incidence was almost zero in all groups except for the cooked wheat starch and 50% sucrose group. comparison to earlier results suggests a possible cariostatic effect of sorghum ...	1988	3165717
the role of insertions/deletions in the evolution of the intergenic region between psba and trnh in the chloroplast genome.	trnh and the intergenic region between trnh and psba of the chloroplast genomes of alfalfa (medicago sativa), fabaceae, and petunia (petunia hybrida), solanaceae, were sequenced and compared to published sequences of that region from other members of those families. a striking feature of these comparisons is the occurrence of insertions/deletions between short, nearly perfect at-rich direct repeats. the directionality of these mutations in the petunia, tobacco and nicotiana debneyi lineages with ...	1988	3180272
the bioavailability of calcium in spinach and calcium-oxalate to calcium-deficient rats.	we estimated the utilization of calcium in spinach and calcium-oxalate to calcium-deficient rats, and the effect of oxalic acid on absorption of dietary calcium by using calcium-deficient rats. the body weight gain of the calcium-deficient rats for 8 days receiving a calcium-deficient diet supplemented with raw-powdered spinach (r-sp), boiled-powdered spinach (b-sp), or calcium-oxalate (ca-ox), and a control diet supplemented with oxalic acid (ox-c) were 4.8, 2.8, 4.9, and 5.1 g, respectively. t ...	1988	3183773
an nadp/thioredoxin system in leaves: purification and characterization of nadp-thioredoxin reductase and thioredoxin h from spinach.	an nadp/thioredoxin system, consisting of nadph, nadp-thioredoxin reductase (ntr), and its thioredoxin, thioredoxin h, has been previously described for heterotrophic plant tissues, i.e., wheat seeds and cultured carrot cells. until now there was no evidence for this system in green leaves. here, we report the identification of protein components of the nadp/thioredoxin system in leaves of several species. thioredoxin h and ntr, which were both recovered in the extrachloroplastic fraction, were ...	1988	3190242
limited proteolysis of the nitrate reductase from spinach leaves.	the functional structure of assimilatory nadh-nitrate reductase from spinach leaves was studied by limited proteolysis experiments. after incubation of purified nitrate reductase with trypsin, two stable products of 59 and 45 kda were observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. the fragment of 45 kda was purified by blue sepharose chromatography. nadh-ferricyanide reductase and nadh-cytochrome c reductase activities were associated with this 45-kda fragment which conta ...	1988	3198646
cu(i) analysis of blue copper proteins.	a simple colorimetric test for the cu(i) content in blue copper proteins is described. the procedure is based on the formation of a complex between cu(i) and 2,2'-biquinoline in an acetic acid medium. analyses of spinach plastocyanin, pseudomonas aeruginosa azurin and rhus vernicifera stellacyanin show that the cysteine residue in the type 1 site does not induce cu(ii) reduction under our conditions. there is evidence in laccase samples for the presence of an endogenous reductant that can reduce ...	1988	3223941
sequence analysis of the junction of the large single copy region and the large inverted repeat in the petunia chloroplast genome.	we have determined the nucleotide sequence at the junction of the large single copy (lsc) region and the right and left members of the large inverted repeat, ira and irb, respectively, of the petunia chloroplast (cp) genome. as in nicotiana debneyi and spinach (zurawski et al. 1984), coding sequences of rps19 of petunia overlap the junction of irb and lsc. immediately into the lsc region upstream of ira in the petunia cp genome are two small insertions relative to n. debneyi that occur at sites ...	1988	3224388
two quick methods for isolation of ribulose-1,5-bisphosphate carboxylase/oxygenase.	methods are described which allow the isolation of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) in a very short time. source of the material was highly impure commercial enzyme in the case of spinach rubisco or bacteria grown from a fermentor in the case of alcaligenes eutrophus rubisco. purity of the enzymes is demonstrated by gel electrophoreses. enzyme isolated from fresh cells gave crystals of excellent diffraction, suitable for x-ray structure analyisis.	1988	3237649
organization and nucleotide sequence of the broad bean chloroplast genes trnl-uag, ndhf and two unidentified open reading frames.	we have determined the nucleotide sequence of a 6.9 kbp bamhi-xbai fragment of broad bean chloroplasts. part of this fragment (subfragment bglii-clai) is known to contain three trna genes (trnl-caa, trnl-uaa and trnf). we have now further identified a gene coding for the third trna(leu) isoacceptor (trnl-uag) which is located close to trnf. the bamhi-xbai fragment also contains the gene for subunit 5 of nadh dehydrogenase (ndhf) and two unidentified open reading frames (orfx and orf48). orfx sha ...	1988	3242868
characterization and in vitro expression of the cytochrome b-559 genes of barley. i. localization and sequence of the genes.	the psbe and psbf genes encoding the 9.4 and 4.4 kd apoproteins of cytochrome b-559 have been located in the chloroplast genome of barley. as in other plant species they are found adjacent to each other in the large single copy region of the chloroplast dna. both the nucleotide sequence and the deduced amino acid sequence for the two polypeptides are identical to that of wheat and more than 95% similar to those of spinach, tobacco and oenothera. the region between the two genes spans 10 nucleoti ...	1988	3256307
structure and expression of spinach leaf cdna encoding ribulosebisphosphate carboxylase/oxygenase activase.	ribulosebisphosphate carboxylase/oxygenase activase is a recently discovered enzyme that catalyzes the activation of ribulose-1,5-bisphosphate carboxylase/oxygenase ["rubisco"; ribulose-bisphosphate carboxylase; 3-phospho-d-glycerate carboxy-lyase (dimerizing), ec 4.1.1.39] in vivo. clones of rubisco activase cdna were isolated immunologically from spinach (spinacea oleracea l.) and arabidopsis thaliana libraries. sequence analysis of the spinach and arabidopsis cdnas identified consensus nucleo ...	1988	3277181
purification and characterization of recombinant spinach acyl carrier protein i expressed in escherichia coli.	expression of plant acyl carrier protein (acp) in escherichia coli at levels above that of constitutive e. coli acp does not appear to substantially alter bacterial growth or fatty acid metabolism. the plant acp expressed in e. coli contains pantetheine and approximately 50% is present in vivo as acyl-acp. we have purified and characterized the recombinant spinach acp-i. nh2-terminal amino acid sequencing indicated identity to authentic spinach acp-i, and there was no evidence for terminal methi ...	1988	3279035
purification and characterization of a novel nadph(nadh)-dependent hydroxypyruvate reductase from spinach leaves. comparison of immunological properties of leaf hydroxypyruvate reductases.	a novel hydroxypyruvate reductase preferring nadph to nadh as a cofactor was purified over 1500-fold from spinach leaf extracts. the enzyme was an oligomer of about 70 kda, composed of two subunits of 38 kda each. the km for hydroxypyruvate (with nadph) was about 0.8 mm in the ph range 5.5-6.5, and 0.3 mm at ph 8.2. the vmax. was highest in the ph range 5.5-6.5 and decreased by about 65% at ph 8.2. above ph 6.0, the enzyme was prone to a strong substrate inhibition by hydroxypyruvate. the reduct ...	1988	3281657
primary structure of glycolate oxidase from spinach.	the primary structure of glycolate oxidase from spinach has been determined. six different types of peptide digest were investigated, utilizing cnbr, proteolytic enzymes, and chemical modifications to change a specificity of cleavage. in total, 90 peptides were purified and analyzed. the studies were aimed at correlation with crystallographic analysis of the same protein carried through in parallel and with cdna studies which utilized initially determined amino acid sequences for synthesis of ol ...	1988	3286256
cdna sequence encoding the 16-kda proteolipid of chromaffin granules implies gene duplication in the evolution of h+-atpases.	vacuolar h+-atpases function in generating protonmotive force across the membranes of organelles connected with the vacuolar system of eukaryotic cells. this family of h+-atpases is distinct from the two other families of h+-atpases, the plasma membrane-type and the eubacterial-type. one of the subunits of the vacuolar h+-atpase binds n,n'-dicyclohexylcarbodiimide (dccd) and has been implicated in the proton-conducting activity of these enzymes. we have cloned and sequenced the gene encoding the ...	1988	2456571
nuclease sp: a novel enzyme from spinach that incises damaged duplex dna preferentially at sites of adenine.	a novel endonuclease has been isolated from extracts of spinach leaves (spinacia oleracea). the enzyme has been purified by a series of column chromatography steps and has a molecular size of approximately 43,000 daltons. the spinach endonuclease cleaved double stranded dna damaged by ultraviolet light or cis-diamminedichloroplatinum (ii) primarily at sites of adenine when end-labelled dna fragments of defined sequence were employed as substrates. the nature of the structural distortion containe ...	1988	2457204
affinity labeling of the allosteric activator site(s) of spinach leaf adp-glucose pyrophosphorylase.	pyridoxal-p has been shown to be an activator of the spinach leaf adp-glucose pyrophosphorylase. it has a higher apparent affinity than the physiological activator 3-phosphoglycerate but only activates the enzyme activity 6-fold whereas 3-phosphoglycerate gives a 25-fold activation. reductive phosphopyridoxylation of the spinach leaf enzyme results in enzyme having less dependence on the presence of activator for activity. labeled pyridoxal-p is incorporated into both the 54- and 51-kilodalton s ...	1988	2826457
organization and structure of the genes for the cytochrome b/c1 complex in purple photosynthetic bacteria. a phylogenetic study describing the homology of the b/c1 subunits between prokaryotes, mitochondria, and chloroplasts.	the cytochrome b/c1 complex is an ubiquitous energy transducing enzyme, part of the electron transport chain of prokaryotes, mitochondria, and chloroplasts (b6/f). in the ancient purple photosynthetic bacteria, the b/c1 complex occupies a central metabolic role, being part of their photosynthetic and respiratory electron transport chain. in rhodobacter the three subunits of the b/c1 complex are fes protein, cytochrome b, and cytochrome c1, and they are encoded by a constitutively expressed opero ...	1988	2831186
a functional five-enzyme complex of chloroplasts involved in the calvin cycle.	a complex of five different enzymes: ribose-phosphate isomerase, phosphoribulokinase, ribulose-bisphosphate carboxylase/oxygenase, phosphoglycerate kinase and glyceraldehyde-phosphate dehydrogenase, has been purified from spinach chloroplasts. these enzymes catalyse five consecutive reactions of the calvin cycle, of which the two reactions catalysed by phosphoribulokinase and ribulose-bisphosphate carboxylase/oxygenase are unique to this cycle. the five-enzyme complex has been purified by succes ...	1988	2834208
on the specificity of pig adrenal ferredoxin (adrenodoxin) and spinach ferredoxin in electron-transfer reactions.	spinach leaf ferredoxin and ferredoxin:nadp oxidoreductase as well as pig adrenodoxin and adrenodoxin reductase have been purified to homogeneity. ferredoxin-nadp reductase and adrenodoxin-nadp reductase can perform the same diaphorase reactions (dichloroindophenol, ferricyanide and cytochrome c reduction) albeit not with the same efficiency. despite the differences in their redox potentials, animal and plant ferredoxins can be used as heterologous substrates by the ferredoxin-nadp reductases fr ...	1988	2839337
comparative amino acid sequence of fructose-1,6-bisphosphatases: identification of a region unique to the light-regulated chloroplast enzyme.	chloroplast fructose-1,6-bisphosphatase (fru-p2-ase) is an essential enzyme in the photosynthetic pathway of carbon dioxide fixation into sugars. the properties of the chloroplast enzyme are clearly distinct from cytosolic gluconeogenic fru-p2-ases. light-dependent activation by way of a ferredoxin/thioredoxin system and insensitivity to amp inhibition are distinctive characteristics of the chloroplast enzyme. however, the chloroplast enzyme shows a high degree of amino acid sequence similarity ...	1988	2840657
characterization of a large inversion in the spinach chloroplast genome relative to marchantia: a possible transposon-mediated origin.	a 7,022 bp bamhi-ecori fragment, located in the inverted repeat of spinach chloroplast, has been sequenced. it contains a 2131 codon open reading frame (orf) homologous to both tobacco orfs 581 and 1708, and to marchantia orf 2136. relative to the marchantia chloroplast genome, spinach orf 2131 is located at the end of a large inversion; the other end point is close to trnl, the position of which is the same in marchantia, tobacco and spinach. in marchantia, two 8 bp direct repeats flanking two ...	1988	2841033
primary structure of cotranscribed genes encoding the rieske fe-s and cytochrome f proteins of the cyanobacterium nostoc pcc 7906.	the thylakoid membrane cytochrome b6-f complex (plastoquinol:oxidized-plastocyanin oxidoreductase, ec 1.10.99.1) catalyzes electron-transfer and proton-translocation reactions essential for oxygenic photosynthesis. we have isolated and determined the nucleotide sequences of the petc and peta genes encoding the rieske fe-s and cytochrome f polypeptides from the filamentous cyanobacterium nostoc pcc 7906. these genes occur as single genomic copies, are tightly linked, and, as indicated by hybridiz ...	1988	2842748
characterization of the manganese o2-evolving complex and the iron-quinone acceptor complex in photosystem ii from a thermophilic cyanobacterium by electron paramagnetic resonance and x-ray absorption spectroscopy.	the mn donor complex in the s1 and s2 states and the iron-quinone acceptor complex (fe2+-q) in o2-evolving photosystem ii (ps ii) preparations from a thermophilic cyanobacterium, synechococcus sp., have been studied with x-ray absorption spectroscopy and electron paramagnetic resonance (epr). illumination of these preparations at 220-240 k results in formation of a multiline epr signal very similar to that assigned to a mn s2 species observed in spinach ps ii, together with g = 1.8 and 1.9 epr s ...	1988	2843222
cloning and sequencing of cdna encoding the mature form of phosphoribulokinase from spinach.	phosphoribulokinase (prk) is a key enzyme in the calvin cycle of autotrophic organisms. we have constructed a spinach leaf cdna library in the phage expression vector, lambda gt11, and used a rabbit polyclonal antibody raised against spinach prk to identify prk clones. analyses of the nucleotide sequences of two antibody-positive clones, 1.47 and 1.35 kb in length, showed that they encode a protein which contains the n-terminal amino acid (aa) sequence [porter et al., arch. biochem. biophys. 245 ...	1988	2843430
plant holo-(acyl carrier protein) synthase.	1. an improved method was developed for the assay of plant holo-(acyl carrier protein) synthase activity, using escherichia coli acyl-(acyl carrier protein) synthetase as a coupling enzyme. 2. holo-(acyl carrier protein) synthase was partially purified from spinach (spinacia oleracea) leaves by a combination of (nh4)2so4 fractionation and anion-exchange and gel-permeation chromatography. 3. the partially purified enzyme had a ph optimum of 8.2 and km values of 2 microm, 72 microm and 3 mm for ap ...	1988	2844150
quantitative analyses of the uncoupling activity of substituted phenols with mitochondria from flight muscles of house flies.	uncoupling activity with flight-muscle mitochondria from house flies was measured for a series of weakly acidic uncouplers (substituted phenols) and compared with the protonophoric potency across lecithin liposomal membranes. the activity was linearly related to the protonophoric potency when such factors as the stability of anionic species in the membrane phase and the difference in the ph conditions of the extramembranous aqueous phase were taken into account. relationships of the flight-muscl ...	1988	2844258
mineral balances of men fed a diet containing fiber in fruits and vegetables and oxalic acid in spinach for six weeks.	in an investigation of the effects of fiber and oxalic acid on weekly mineral balances, 12 men consumed two diets consisting of natural foods for 6 wk each in a crossover design. one diet contained about 25 g neutral detergent fiber (ndf) in fruits and vegetables and included 100 g spinach, which is high in oxalic acid, every other day. the second diet was a low fiber diet that contained about 5 g ndf and the same amount of spinach as the first diet. on the basis of mean values for 6 wk, balance ...	1988	2846801
glutathione reductase: solvent equilibrium and kinetic isotope effects.	glutathione reductase catalyzes the nadph-dependent reduction of oxidized glutathione (gssg). the kinetic mechanism is ping-pong, and we have investigated the rate-limiting nature of proton-transfer steps in the reactions catalyzed by the spinach, yeast, and human erythrocyte glutathione reductases using a combination of alternate substrate and solvent kinetic isotope effects. with nadph or gssg as the variable substrate, at a fixed, saturating concentration of the other substrate, solvent kinet ...	1988	2848577
amino-terminal sequence of spinach chloroplast fructose-1,6-bisphosphatase.	the sequence of the nh2-terminal 25-amino acid residues of purified spinach chloroplast fructose-1,6-bisphosphatase was determined by automated edman degradation. the amino acid sequence is as follows: ala-ala-val-gly-glu-ala-ala-thr-gln-thr-lys-ala- arg-thr-arg-ser-lys-tyr-glu-ile-glu-thr-leu-thr-gly. a comparison of this sequence with the corresponding region of pig kidney and yeast (saccharomyces cerevisiae) fructose-1,6-bisphosphatases shows that the sequence of residues 1-19 of the chloropl ...	1988	2856482
characterization of a chloroplast sequence-specific dna binding factor.	the large subunit of ribulose 1,5-bisphosphate carboxylase (rbcl) and the beta subunit of chloroplast atp synthase (atpb) are encoded by divergently transcribed genes on the plastid genome. we have identified dna binding factors specific for sequences located in the intergenic region between these two genes. soluble plastid extracts from pea or whole cell extracts from maize protected a maize chloroplast dna probe containing the 160-base pair region between the 5' ends of rbcl and atpb genes fro ...	1988	2897366
structure of the atp-synthase from chloroplasts and mitochondria studied by electron microscopy.	the structure of the atp-synthase, f0f1, from spinach chloroplasts and beef heart mitochondria has been investigated by electron microscopy with negatively stained specimens. the detergent-solubilized atp-synthase forms string-like structures in which the f0 parts are aggregated. in most cases, the f1 parts are arranged at alternating sides along the string. the f0 part has an approximate cylindrical shape with heights of 8.3 and 8.9 nm and diameters of 6.2 and 6.4 nm for the chloroplast and mit ...	1988	2898840
kinetic characterization, stereoselectivity, and species selectivity of the inhibition of plant acetyl-coa carboxylase by the aryloxyphenoxypropionic acid grass herbicides.	the selective grass herbicides diclofop, haloxyfop, and trifop were found to be potent reversible inhibitors of acetyl-coa carboxylase from the susceptible species barley, corn, and wheat. kis values with variable concentrations of acetyl-coa ranged from 0.01 to 0.06 microm at ph 8.5 depending on the species of grass. inhibition of the wheat enzyme by diclofop was noncompetitive versus acetyl-coa with kis less than kii and noncompetitive versus mgatp and bicarbonate, but with kis approximately e ...	1988	2901248
rubredoxin as an intermediary electron carrier for nitrate reduction by nad(p)h in clostridium perfringens.	the nad(p)h-dependent nitrate reductase system in clostridium perfringens was reconstituted with rubredoxin (rd), nitrate reductase (nar), and an unadsorbed fraction, on a deae-cellulose column, of the extract (designated as fraction a), under nitrogen gas. ferredoxin in place of rd was not effective as an electron carrier in this reconstituted system. nad(p)h-dependent nitrate reducing activity was also obtained by replacing fraction a with ferredoxin-nadp+ reductase from spinach. we propose th ...	1988	2902073
analysis of cdna clones encoding the entire precursor-polypeptide for ferredoxin:nadp+ oxidoreductase from spinach.	in this paper, we report the structural characterization of several spinach ferredoxin-nadp+ oxidoreductase (fnr) cdnas ranging in size from 0.9 to 1.5 kilobases. a comparison of the deduced amino acid sequence with the known amino acid sequence determined for the spinach protein establishes that 1.4-1.5 kpb inserts span the full length of the mature protein (314 amino acid residues; mr = 35,382). these also include an n-terminal 55 amino acid transit peptide as well as maximally 171 and 214 nuc ...	1988	2969782
calcium absorbability from spinach.	the absorbability of calcium from spinach was compared with the absorbability of ca from milk in 13 healthy adults in a randomized cross-over design in which the test meal of either milk or spinach had 200 mg of ca labeled with 45ca. absorption was measured by the standard double-isotope method in which both the test food and the miscible ca pool are labeled with different ca tracers. measurement of both ca and oxalate in our test spinach revealed a very slight stoichiometric excess of oxalate; ...	1988	3354496
effects of slow release carbohydrates in the form of bean flakes on the evolution of hunger and satiety in man.	this study was undertaken to test the effects of plausible meals containing slow release starches in the form of bean flakes on plasma glucose and hunger in man. in a first study, volunteers consumed a hachis paramentier (shepherd's pie) containing either bean purée or potato purée. after the meal containing potato, plasma glucose levels rose sharply, peaked at 30-45 min and fell below initial levels 2 to 3 h later. with bean purée there was a low, sustained increase in blood glucose. in a secon ...	1988	3355122
excretion of n-mononitrosopiperazine after low level exposure to piperazine in air: effects of dietary nitrate and ascorbate.	the secondary amine piperazine may be nitrosated in vivo, following oral intake or occupational exposure by inhalation. the suspected carcinogen n-mononitrosopiperazine could be formed in the human stomach, and in part excreted in the urine. in this study, 0.4 microgram n-mononitrosopiperazine, determined by gas chromatography-thermal energy analysis, was observed in the urine in one of four volunteers, at an experimental exposure by inhalation of 0.3 mg piperazine/m3. the intake of spinach and ...	1988	3358264
expression of the rpl23, rpl2 and rps19 genes in spinach chloroplasts.	the expression of the spinach rpl23, rpl2 and rps19 chloroplast genes has been studied. the rpl23 gene identified in tobacco and marchantia, is split into two overlapping reading frames in spinach. s1 mapping has shown that initiation sites could occur upstream of each reading frames. a large transcription unit is also present covering the rpl2 and rps19 genes. the rps19 and rpl2 gene products are identified by nh2-terminal amino acid sequences. they correspond to spinach chloroplast ribosomal p ...	1988	3362671
biologically active fluorescent derivatives of spinach calmodulin that report calmodulin target protein binding.	spinach calmodulin (cam) has been labeled at cysteine-26 with the sulfhydryl-selective probe 2-(4-maleimidoanilino)naphthalene-6-sulfonic acid (mians) to produce mians-cam. the interaction of mians-cam with cam binding proteins was studied by fluorescence enhancement accompanying the protein-protein interactions. mians-cam bound to smooth muscle myosin light-chain kinase with a kd of 9 nm, causing a 4.6-fold fluorescence enhancement. caldesmon bound with a kd of 250 nm, causing a 2-fold fluoresc ...	1988	3365375
enumeration and isolation of cellulolytic and hemicellulolytic bacteria from human feces.	the fibrolytic microbiota of the human large intestine was examined to determine the numbers and types of cellulolytic and hemicellulolytic bacteria present. fecal samples from each of five individuals contained bacteria capable of degrading the hydrated cellulose in spinach and in wheat straw pretreated with alkaline hydrogen peroxide (ahp-ws), whereas degradation of the relatively crystalline cellulose in whatman no. 1 filter paper (pmc) was detected for only one of the five samples. the mean ...	1988	3415224
recognition of prokaryotic transcription terminators by spinach chloroplast rna polymerase.	to determine whether chloroplast rna polymerase will accurately terminate transcription in vitro, we have fused the spinach chloroplast rbcl promoter to the 3' end of the rbcl gene as well as to various factor independent transcription terminators from e. coli. transcription of the rbcl minigene did not result in production of the expected 265 nucleotide rna. however, the spinach chloroplast rna polymerase did terminate transcription with varying efficiency at the thra, rrnb, rrnc and gene 32 te ...	1988	2843817
identification of an escherichia coli s1-like protein in the spinach chloroplast ribosome.	antibodies directed against e. coli ribosomal protein s1 were used in immunoblotting assays to search for an s1-like protein in the ribosome of spinach chloroplast. an immunological cross-reaction was reproducibly detected on the blots and inhibition experiments have demonstrated its specificity. the chloroplastic ribosomal protein which has epitopes common to antigenic determinants of the e. coli protein s1 was identified as being protein s2/s3.	1988	24277593
transcription study of the genes encoded in the region of the junction between the large single copy and the inverted repeat a of spinach chloroplast dna.	the expression of the psba, trnh-gug and rps19' genes from spinach chloroplasts, coding respectively for the 32 kda protein, the trna(his) (gug), and the putative ribosomal protein cs19', has been studied by cloning, northern hybridization and 3' and 5' s1 mapping experiments.it is demonstrated that the putative transcription termination signal of the psba gene does not function as a rho-independent terminator of transcription in e. coli, whatever its orientation.evidence is presented suggesting ...	1988	24277592
chlorella chloroplast dna sequence containing a gene for the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase and a part of a possible gene for the β' subunit of rna polymerase.	the sequence of a 2782 bp fragment of the chloroplast genome of chlorella ellipsoidea has been determined. the region includes the entire gene (rbcl) for the large subunit (ls) of ribulose-1,5-bisphosphate carboxylase/oxygenase and a sequence (rpoc-like) similar to part of the gene for the subunit of e. coli rna polymerase which is oriented in same direction as rbcl. the arrangement is rpoc-like - 446 bp - rbcl. the rbcl gene codes for a polypeptide of 475 amino acids whose sequence shows 88% ho ...	1988	24277518
a starch deficient mutant of arabidopsis thaliana with low adpglucose pyrophosphorylase activity lacks one of the two subunits of the enzyme.	a starch deficient mutant of arabidopsis thaliana (l.) heynh. has been isolated in which leaf extracts contain only about 5% as much activity of adpglucose pyrophosphorylase (ec 2.7.7.27) as the wild type. a single, nuclear mutation at a previously undescribed locus designated adg2 is responsible for the mutant phenotype. although the mutant contained only 5% as much adpglucose pyrophosphorylase activity as the wild type, it accumulated 40% as much starch when grown in a 12 hour photoperiod. the ...	1988	16666440
isolation and characterization of a starchless mutant of arabidopsis thaliana (l.) heynh lacking adpglucose pyrophosphorylase activity.	a mutant of arabidopsis thaliana lacking adpglucose pyrophosphorylase activity (ec 2.7.7.27) was isolated (from a mutagenized population of plants) by screening for the absence of leaf starch. the mutant grows as vigorously as the wild type in continuous light but more slowly than the wild type in a 12 hours light/12 hours dark photoperiod. genetic analysis showed that the deficiency of both starch and adpglucose pyrophosphorylase activity were attributable to a single, nuclear, recessive mutati ...	1988	16666044
glutamine transport and the role of the glutamine translocator in chloroplasts.	the transport of l-[(14)c]glutamine in oat (avena sativa l.) and spinach (spinacia oleracea l.) chloroplasts was studied by a conventional single-layer and a newly developed stable double-layer silicone oil filtering system. [(14)c]glutamine was actively transported into oat chloroplasts against a concentration gradient. metabolite uptake was greatly affected by the endogenous dicarboxylate pools, which could be easily changed by preloading the chloroplast with specific exogenous substrate. glut ...	1988	16666419
protection of photosynthetic o2 evolution against heat inactivation: the role of chloride, ph and coupling status.	heat inactivation of photosynthetic o2 evolution was studied in isolated thylakoids from spinach (spinacia oleracea) and mangrove (avicennia marina) leaves. different temperatures, salt, ph and uncoupler effects were investigated. from these results and others in the literature it was concluced that chloride loss from the membrane and, more specifically, the oxygen-evolving complex of photosystem ii, may be the cause of inhibition of oxygen evolution during heat inactivation.	1988	24430859
oxygen-18 and deuterium labeling studies of choline oxidation by spinach and sugar beet.	chenopods synthesize betaine by a two-step oxidation of choline: choline --> betaine aldehyde --> betaine. the pathway is chloroplastic; the first step has been shown in isolated spinach (spinacia oleracea l.) chloroplasts to be o(2)- and light-dependent, the role of light being to provide reducing power (p weigel, ea weretilnyk, ad hanson 1988 plant physiol 86: 54-60). here, we report use of in vivo(18)o- and (2)h-labeling in conjunction with fast atom bombardment mass spectrometry to test for ...	1988	16666370
mechanisms for light-dependent regulation of ribulose-1,5-bisphosphate carboxylase activity and photosynthesis in intact leaves.	the mechanisms involved in the in vivo light-dependent regulation of ribulose-1,5-bisphosphate (rbup(2)) carboxylase [3-phospho-d-glycerate carboxy-lyase (dimerizing), ec 4.1.1.39] activity in intact leaves were studied. in the three species examined, phaseolus vulgaris, beta vulgaris, and spinacea oleracea, the regulated level of rbup(2) carboxylase activity (assayed in vitro with saturating substrate) was highly correlated (r = 0.96) with the rate of net co(2) uptake of the corresponding leave ...	1988	16593934
preparation and characterization of envelope membranes from nongreen plastids.	we have developed a reliable procedure for the purification of envelope membranes from cauliflower (brassica oleracea l.) bud plastids and sycamore (acer pseudoplatanus l.) cell amyloplasts. after disruption of purified intact plastids, separation of envelope membranes was achieved by centrifugation on a linear sucrose gradient. a membrane fraction, having a density of 1.122 grams per cubic centimeter and containing carotenoids, was identified as the plastid envelope by the presence of monogalac ...	1988	16666372
dihydroxyacetone phosphate reductase in plants.	two forms of dihydroxyacetone phosphate reductase are present in spinach, soybean, pea, and mesophyll cells of corn leaves. an improved homogenizing medium was developed to measure this activity. the enzyme was detectable only after dialysis of the 35 to 70% saturated (nh(4))(2)so(4) fraction and the two forms were separated by chromatography on either deae cellulose or sephacryl s-200. about 80% of the reductase was one form in the chloroplast and the rest was a second form in the cytosol as de ...	1988	16665901
characterization of the rna required for biosynthesis of delta-aminolevulinic acid from glutamate : purification by anticodon-based affinity chromatography and determination that the uuc glutamate anticodon is a general requirement for function in ala biosynthesis.	the heme and chlorophyll precursor delta-aminolevulinic acid acid (ala) is formed in plants and algae from glutamate in a process that requires at least three enzyme components plus a low molecular weight rna which co-purifies with the trna fraction during deae-cellulose column chromatography. rna that is effective in the in vitro ala biosynthetic system was extracted from several plant and algal species that form ala via this route. in all cases, the effective rna contained the uuc glutamate an ...	1988	16665935
catalysis of ribulosebisphosphate carboxylase/oxygenase activation by the product of a rubisco activase cdna clone expressed in escherichia coli.	ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) activase activity was obtained from a partially purified extract of escherichia coli transformed with a 1.6-kilobase spinach (spinacia oleracea l.) cdna clone. this activity was atp-dependent. catalysis of rubisco activation by spinach and cloned rubisco activase was accompanied by the same extent of carboxyarabinitol bisphosphate-trapped (14)co(2) as occurred in spontaneous activation, indicating that rubisco carbamylation is one facet o ...	1988	16666245
isolation of dihydroxyacetone phosphate reductase from dunaliella chloroplasts and comparison with isozymes from spinach leaves.	a dihydroxyacetone phosphate (dhap) reductase has been isolated in 50% yield from dunaliella tertiolecta by rapid chromatography on diethylaminoethyl cellulose. the activity was located in the chloroplasts. the enzyme was cold labile, but if stored with 2 molar glycerol, most of the activity was restored at 30 degrees c after 20 minutes. the spinach (spinacia oleracea l.) reductase isoforms were not activated by heat treatment. whereas the spinach chloroplast dhap reductase isoform was stimulate ...	1988	16666401
chalcone synthases from spinach (spinacia oleracea l.) : ii. immunofluorescence and immunogold localization.	the distribution of the two chalcone synthases in leaves ofspinacia oleracea l. was studied at both the tissue and the subcellular level using immunofluorescence and immunogold techniques. neither technique differentiated between the two enzyme forms. the chalcone synthases are located in the upper and the lower epidermis and to a minor extent in the subepidermal layers. traces of the two enzyme forms may be present in the residual mesophyll. this distribution is independent of leaf age. a simil ...	1988	24226692
chalcone synthases from spinach (spinacia oleracea l.) : i. purification, peptide patterns, and immunological properties of different forms.	the two chalcone-synthase forms from leaves ofspinacia oleracea l. were purified to apparent homogeneity. antibodies were raised against both proteins in rabbits. the specificity of the antibodies was tested using immunotitration, immunoblotting, and immunoelectrophoresis techniques. the antibodies exhibited exclusive specificity for chalcone synthase and did not discriminate between the two antigens. the homodimeric chalcone synthases had the same subunit molecular weight but differed in their ...	1988	24226691
effect of high light intensities on oxygen evolution and the light activation of nadp-malate dehydrogenase in intact spinach chloroplasts.	the factors limiting the photosynthetic carbon metabolism of intact spinach (spinacia oleracea l.) chloroplasts after a high-light pretreatment have been studied. photosynthetic co2 fixation was decreased and became more sensitive to the inhibitory effect of the cyclic-electron-flow inhibitor, antimycin a. depending on the extent of photoinhibition, changing the balance of linear to cyclic electron flow by adding oxaloacetate and antimycin a either did not relieve, or partially relieved the phot ...	1988	24226683
characterization of elemental sulfur in isolated intact spinach chloroplasts.	incubation of intact spinach (spinacia oleracea l.) chloroplasts in the presence of (35)so(4) (2-) resulted in the light-dependent formation of a chloroform-soluble sulfur-containing compound distinct from sulfolipid. we have identified this compound as the most stable form (s(8)) of elemental sulfur (s(0), valence state for s = o) by mass spectrometry. it is possible that elemental sulfur (s(0)) was formed by oxidation of bound sulfide, i.e. after the photoreduction of sulfate to sulfide by int ...	1988	16666485
carbon dioxide-induced oscillations in fluorescence and photosynthesis: role of thylakoid membrane energization in regulation of photosystem ii activity.	the response of co(2) fixation to a sudden increase in ambient co(2) concentration has been investigated in intact leaf tissue from spinach (spinacia oleracea) using a dual channel infrared gas analyzer. simultaneous with these measurements, changes in fluorescence emission associated with a weak, modulated measuring beam were recorded. application of brief (2-3 seconds) dark intervals enabled estimation of the dark fluorescence level (f(o)) under both steady state and transient conditions. the ...	1988	16666432
purification and assay of rubisco activase from leaves.	ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) activase protein was purified from spinach leaves by ammonium sulfate precipitation and ion exchange fast protein liquid chromatography. this resulted in 48-fold purification with 70% recovery of activity and yielded up to 18 milligrams of rubisco activase protein from 100 grams of leaves. based on these figures, the protein comprised approximately 2% by weight of soluble protein in spinach (spinacia oleracea l.) leaves. the preparations ...	1988	16666412
phosphate sequestration by glycerol and its effects on photosynthetic carbon assimilation by leaves.	glycerol induced a limitation on photosynthetic carbon assimilation by phosphate when supplied to leaves of barley (hordeum vulgare l.) and spinach (spinacia oleracea l.). this limitation by phosphate was evidenced by (i) reversibility of the inhibition of photosynthesis by glycerol by feeding orthophosphate (ii) a decrease in light-saturated rates of photosynthesis and saturation at a lower irradiance, (iii) the promotion of oscillations in photosynthetic co2 assimilation and in chlorophyll flu ...	1988	24220742
effects of irradiance and methyl viologen treatment on atp, adp, and activation of ribulose bisphosphate carboxylase in spinach leaves.	since activation of ribulose bisphosphate carboxylase (rubisco) by rubisco activase is sensitive to atp and adp in vitro, we aimed to test the correlation between atp level and rubisco activation state in intact leaves of spinacia oleracea l. in response to changes in irradiance and after feeding the electron acceptor methyl viologen. leaves were exposed to various irradiances for 45 minutes at atmospheric partial pressures of co(2) and o(2). after measuring the rate of co(2) assimilation, leave ...	1988	16666396
ferredoxin cross-links to a 22 kd subunit of photosystem i.	we have used a cross-linking approach to study the interaction of ferredoxin (fd) with photosystem i (psi). the cross-linking reagent n-ethyl-3-(3-dimethylaminopropyl) carbodiimide was found to cross-link spinach fd to a 22 kilodalton subunit of psi in both isolated spinach (spinacia oleracea) psi complexes and spinach thylakoid membranes. the product had an apparent molecular weight of 38 kilodaltons on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was identified as a cross-link ...	1988	16666389
hydrophobic-cluster analysis of plant protein sequences. a domain homology between storage and lipid-transfer proteins.	hydrophobic-cluster analysis was used to characterize a conserved domain located near the c-terminal amino acid sequence of wheat (triticum aestivum) storage proteins. this domain was transformed into a linear template for a global search for similarities in over 5200 protein sequences. in addition to proteins that had already been found to exhibit homology to wheat storage proteins, a previously unreported homology was found with non-specific lipid-transfer proteins from castor bean (ricinus co ...	1988	3214430
detection of polypeptides associated with the cold acclimation process in spinach.	exposure of spinach (spinacia oleracea) seedlings to 5 degrees c for several days has previously been shown to induce a greater tolerance to the stresses of extracellular freezing. associated with this response to low temperature, termed cold acclimation, was a subtle shift in protein synthesis and altered polypeptide composition. two-dimensional gel electrophoresis was used to study the changes in spinach leaf tissue protein synthesis in an effort to identify polypeptides that may play a centra ...	1988	2471636
effects of temperature pretreatment in the dark on photosynthesis of the intact spinach chloroplast.	isolated, intact spinach (spinacia oleracea l. var. "long standing bloomsdale") chloroplasts were heated in the dark and the effect of this treatment on photosynthetic activities was determined at 25 degrees c. dark incubation of the chloroplasts for 10 minutes at 35 degrees c and ph 8.1 resulted in a 50% decline in co(2) photoassimilation. this decline in photosynthetic performance was dependent upon time, temperature, and medium ph with the optimum effect at acidic ph values. photosynthetic de ...	1988	16666267
chloroplast osmotic adjustment and water stress effects on photosynthesis.	previous studies have suggested that chloroplast stromal volume reduction may mediate the inhibition of photosynthesis under water stress. in this study, the effects of spinach (spinacia oleracea, var ;winter bloomsdale') plant water deficits on chloroplast photosynthetic capacity, solute concentrations in chloroplasts, and chloroplast volume were studied. in situ (gas exchange) and in vitro measurements indicated that chloroplast photosynthetic capacity was maintained during initial leaf water ...	1988	16666266
ion homeostasis in chloroplasts under salinity and mineral deficiency: ii. solute distribution between chloroplasts and extrachloroplastic space under excess or deficiency of sulfate, phosphate, or magnesium.	spinach (spinacia oleracea var "yates") plants grown hydroponically were exposed to an excess or deficiency of various mineral ions. solutes were measured in leaf extracts and in isolated intact chloroplasts. under phosphate (120 millimoles per liter nah(2) po(4)), sulfate (200 millimolar per liter (na(2) so(4)), or magnesium excess (150 millimolar per liter mgcl(2)), concentrations of these ions in leaf extracts increased, but in chloroplasts, concentrations of all ions remained constant. conce ...	1988	16666233
nucleotide sequence of cdna clones encoding the complete precursor for the "10-kda" polypeptide of photosystem ii from spinach.	by screening lambda gt11 cdna expression libraries prepared from poly(a+) rna of illuminated (4 and 16 h) spinach seedlings (spinacia oleracea var. monatol), we have recovered phage containing inserts corresponding to the complete "10-kda" precursor polypeptide associated with the water oxidizing photosystem ii. the amino acid sequence deduced from the nucleotide sequence indicates a polypeptide of 140 amino acid residues (15.0 kda). the mature protein is predicted to consist of 99 amino acid re ...	1988	2839473
regulation of ribulose-1,5-bisphosphate carboxylase activity by the activase system in lysed spinach chloroplasts.	ribulose-1,5-bisphosphate (rubp) carboxylase in lysed spinach (spinacia oleracea l. cv virtuosa) chloroplasts that had been partly inactivated at low co(2) and mg(2+) by incubating in darkness with 4 millimolar partially purified rubp was reactivated by light. if purified rubp was used to inhibit dark activation of the enzyme, reactivation by light was not observed unless fructose-1,6-bisphosphate, atp, or adp plus inorganic phosphate were also added. presumably, adp plus inorganic phosphate act ...	1988	16666184
ph and kinetic studies of chloroplast sedoheptulose-1,7-bisphosphatase from spinach (spinacia oleracea).	the aim of this paper is to study some steady-state kinetic properties of sedoheptulose-1,7-bisphosphatase, its ph-dependence and the effect of a substrate analogue, fructose 2,6-bisphosphate. studies were carried out with sedoheptulose 1,7-bisphosphate and with fructose 1,6-bisphosphate, an alternative substrate. the pk values are identical for both substrates, and fructose 2,6-bisphosphate behaves like a competitive inhibitor. these results suggest that there exists a unique active site for ei ...	1988	2844169
differential inhibition and activation of two leaf dihydroxyacetone phosphate reductases : role of fructose 2,6-bisphosphate.	the chloroplastic and cytosolic forms of spinach (spinacia oleracea cv long standing bloomsdale) leaf nadh:dihydroxyacetone phosphate (dhap) reductase were separated and partially purified. the chloroplastic form was stimulated by dithiothreitol, reduced thioredoxin, dihydrolipoic acid, 6-phosphogluconate, and phosphate; the cytosolic isozyme was stimulated by fructose 2,6-bisphosphate but not by reduced thioredoxin. end product components that severely inhibited both forms of the reductase incl ...	1988	16666150
spectral, photophysical, and stability properties of isolated photosystem ii reaction center.	photosystem ii reaction center (rc) preparations isolated from spinach (spinacea oleracea) by the nanba-satoh procedure (o nanba, k satoh 1987 proc natl acad sci usa 84: 109-112) are quite labile, even at 4 degrees c in the dark. simple spectroscopic criteria were developed to characterize the native state of the material. degradation of the rc results in (a) blue-shifting of the red-most absorption maximum, (b) a shift of the 77 k fluorescence maximum from approximately 682 nm to approximately ...	1988	16666138