| 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 |
| somatostatin-like material is present in flowering plants. | extracts of spinach contain somatostatin (srif)-related material (6-80 pg/g wet wt). the srif-related material, when purified on hplc, was recovered as two major mol wt forms; one that eluted with a retention time similar to that of synthetic srif-28 and reacted in both n- and c-terminal-specific immunoassays, and a second peak that eluted with a retention time similar to that of srif-14 and reacted only in the c-terminal immunoassays. the purified material was active in a sensitive bioassay, an ... | 1985 | 2864240 |
| use of streptavidin to detect biotin-containing proteins in plants. | a procedure to detect biotinyl proteins after fractionation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was developed. proteins were immobilized on nitrocellulose and biotin-containing proteins were detected by probing with 125i-streptavidin. using this procedure a small survey of biotinyl protein in plants was undertaken. in total four biotin-containing proteins were detected in higher plants of molecular weights 62,000, 50,000, 34,000, and 31,000. these biotinyl proteins were ... | 1985 | 2866733 |
| properties of the cyanobacterial coupling factor atpase from spirulina platensis. i. electrophoretic characterization and reconstitution of photophosphorylation. | the coupling factor atpase (f1) from photosynthetic membranes of the cyanobacterium spirulina platensis was purified to homogeneity by a combination of ion-exchange chromatography and sucrose density gradient centrifugation. the atpase activity of purified spirulina f1 is latent but can be elicited by trypsin treatment, resulting in specific activities (caatpase) of 27-37 mumol pi min-1 mg protein-1. on denaturing sodium dodecyl sulfate-polyacrylamide gradient gels, spirulina f1 is resolved into ... | 1986 | 2868694 |
| analysis of promoter regions for the spinach chloroplast rbcl, atpb and psba genes. | a promoter-deletion derivative of the spinach trnm2 gene was used for the identification and characterization of the promoter regions for the spinach chloroplast rubisco large subunit (rbcl), atpase beta-subunit (atpb) and qb-polypeptide (psba) genes. the dna sequences 5' upstream from the transcriptional start sites of these genes share homology with the ctp1 and ctp2 arrangement found for the trnm2 transcription unit and the canonical escherichia coli '-10' and '-35' promoter regions. syntheti ... | 1985 | 2868888 |
| genes encoding the beta and epsilon subunits of the proton-translocating atpase from anabaena sp. strain pcc 7120. | the genes encoding the beta (atpb) and epsilon (atpe) subunits of the atpase from the cyanobacterium anabaena sp. strain pcc 7120 were cloned, and their sequences were determined. atpb and atpe are each single-copy genes in the anabaena genome. the two genes are separated by a 96-base-pair intergenic spacer and transcribed as a single mrna of 2.3 kilobases that initiates approximately 200 base pairs upstream of the atpb coding region. the predicted translation product of atpb has 81 and 68% amin ... | 1987 | 2878921 |
| stable structure of thermophilic proton atpase beta subunit. | f1-atpase is the major enzyme for atp synthesis in mitochondria, chloroplasts, and bacterial plasma membranes. f1-atpase obtained from thermophilic bacterium ps3 (tf1) is the only atpase which can be reconstituted from its primary structure. its beta subunit constitutes the catalytic site, and is capable of forming hybrid f1's with e. coli alpha and gamma subunits. since the stability of tf1 resides in its primary structure, we cloned a gene coding for tf1, and the primary structure of the beta ... | 1986 | 2880841 |
| the halobacterial h+-translocating atp synthase relates to the eukaryotic anion-sensitive h+-atpase. | the h+-translocating atp synthase of halobacterium halobium (y. mukohata and m. yoshida (1987) j. biochem. 102, 797-802) includes a catalytic moiety of 320 kda which is isolated as an azide-insensitive atpase (t. nanba and y. mukohata (1987) j. biochem. 102, 591-598). the polyclonal antibody against this archaebacterial atpase cross-reacts with the anion-sensitive h+-atpase of red beet, beta vulgaris, tonoplast as well as with another archaebacterial atpase from sulfolobus acidocaldarius. the af ... | 1987 | 2892466 |
| 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 |
| 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 |
| paps-reductase from escherichia coli: characterization of the enzyme as probe for thioredoxins. | paps-reductase from escherichia coli was employed to detect thioredoxins from pro- and eukaryotic organisms. a simple method for the isolation of this enzyme and properties of the enzymatic assay were described. a comparison between thioredoxins detected by the paps-reductase and the fructose-bisphosphatase or nadp malate dehydrogenase was used to assess the validity of the test. the high cross-reactivity of the bacterial enzyme was useful in the purification of heterologous thioredoxins from sp ... | 1987 | 2953134 |
| 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 |
| further characterisation of the fad and fe2s2 redox centres of component c, the nadh:acceptor reductase of the soluble methane monooxygenase of methylococcus capsulatus (bath). | the absorbance contributions of the fad and fe2s2 redox centres of component c of the soluble methane monooxygenase complex have been resolved, using mersalyl to destroy the fe2s2 centre. the fe2s2 seems to be very similar to that of spinach ferredoxin, by its absorbance and electron paramagnetic resonance (epr) spectra, and the fad semiquinone is a neutral semiquinone. spectrophotometry near room temperature and epr spectroscopy near liquid-helium temperature allow the three redox couples of co ... | 1985 | 2982614 |
| oxidation of microbial iron-sulfur centers by the myeloperoxidase-h2o2-halide antimicrobial system. | myeloperoxidase, h2o2, and a halide (chloride, bromide, or iodide) form a potent microbicidal system that contributes to the antimicrobial activity of neutrophils. the mechanism of toxicity is not completely understood. powerful oxidants are formed that presumably attack the microbe at a variety of sites. among the consequences of this attack is the release of a large proportion of 59fe of prelabeled organisms. we report here that the myeloperoxidase-h2o2-halide system oxidizes the iron-sulfur c ... | 1985 | 2982737 |
| phosphate dependency of phosphofructokinase 2. | experiments performed at micromolar concentrations of inorganic phosphate support the conclusion that liver phosphofructokinase 2 would be completely inactive in the absence of inorganic phosphate or arsenate. the concentration of inorganic phosphate that allowed half-maximal activity decreased with increasing ph, being approximately 0.11 mm at ph 6.5 and 0.05 mm at ph 8. the effect of phosphate was to increase v and to decrease km for fructose 6-phosphate, without affecting km for atp. citrate ... | 1985 | 2983989 |
| enzymic synthesis of the 4fe-4s clusters of clostridium pasteurianum ferredoxin. | ex novo enzymic synthesis of the two 4fe-4s clusters of clostridium pasteurianum ferredoxin has been achieved by incubation of the apoprotein with catalytic amounts of the sulfurtransferase rhodanese in the presence of thiosulfate, dl-dihydrolipoate and ferric ammonium citrate. this enzymic reconstitution procedure was compared to a chemical one, in which the enzyme was replaced by sodium sulfide. a further comparison was made with the results previously obtained in the enzymic synthesis of the ... | 1985 | 2983992 |
| antimycin-resistant alternate electron pathway to plastocyanin in bovine-heart complex iii. | bovine-heart complex iii can catalyze the reduction of spinach plastocyanin by a decyl analog of ubiquinol-2 at a rate comparable with the rate of plastocyanin reduction by plastoquinol as catalyzed by the cytochrome b6-f complex purified from spinach leaves. this plastocyanin reduction as catalyzed by complex iii was almost completely inhibited by myxothiazol at stoichiometric concentrations, partially inhibited by uhdbt (5-n-undecyl-6-hydroxy-4,7-dioxobenzothiazole) and funiculosin, and was re ... | 1985 | 2989259 |
| the chloroplast genome of carthamus tinctorius. | a physical map of safflower (carthamus tinctorius l.) chloroplast dna has been generated using sali, psti, kpni and hindiii restriction endonucleases. southern blots to single and double digests by these enzymes were hybridized with 32p-dctp nick-translated kpni probes, which were individually isolated from agarose gels. the plastid genome was found to be circular (151 kbp), to contain a repeated sequence of about 25 kbp, and to have small and large single copy regions of approximately 20 and 81 ... | 1985 | 3001501 |
| in vitro transcription initiation of the spinach chloroplast 16s rrna gene at two tandem promoters. | two potential prokaryotic promoters, p1 and p2, are characterized 164 and 114 bp upstream of the spinach chloroplast 16s rrna gene. the strengths of these promoters, calculated according to an homology score established for e. coli rna-polymerase, are identical. experiments performed with a taq i-dna fragment, containing 16 bp of the 16s rdna and 243 bp upstream of the gene, give evidence that in vitro, e. coli rna-polymerase starts transcription at these two promoters. these results are based o ... | 1985 | 3001651 |
| amino acid sequence similarity between spinach chloroplast and mammalian gluconeogenic fructose-1,6-bisphosphatase. | chloroplast fructose-1,6-bisphosphatase is an essential enzyme in the photosynthetic pathway of carbon dioxide fixation into sugars and the properties of this enzyme are clearly distinct from cytosolic gluconeogenic fructose-1,6-bisphosphatase. light-dependent activation via a ferredoxin/thioredoxin system and insensitivity to inhibition by amp are unique characteristics of the chloroplast enzyme. in the present study, purified spinach chloroplast fructose-1,6-bisphosphatase was reduced, s-carbo ... | 1985 | 3002349 |
| amino acid sequence homology among fructose-1,6-bisphosphatases. | the hydrolysis of fructose 1,6-bisphosphate to fructose 6-phosphate is a key reaction of carbohydrate metabolism. the enzyme that catalyzes this reaction, fructose-1,6-bisphosphatase, appears to be present in all forms of living organisms. regulation of the enzyme activity, however, occurs by a variety of distinct mechanisms. these include amp inhibition (most sources), cyclic amp-dependent phosphorylation (yeast), and light-dependent activation (chloroplast). in the present studies, we have mad ... | 1986 | 3008716 |
| cadmium in sludges used as fertilizer. | in intensively populated countries efficient sewage treatment is essential to protect river quality. an inevitable by-product is sewage sludge which has to be disposed of safely and economically. utilisation of sludge as a fertilizer of agricultural land is the most economic disposal route for inland sewage-treatment works and also benefits farmers by providing a cheap manure. much of the cadmium in wastewater is concentrated into sludge which consequently contains higher concentration of cadmiu ... | 1986 | 3015670 |
| mechanism of activation by anions of phosphoglycolate phosphatases from spinach and human red blood cells. | phosphoglycolate phosphatases from spinach and human red blood cells show a number of common features not often found in enzymes. both enzymes are activated more than 50-fold by millimolar concentrations of cl-. other inorganic anions and a number of carboxylic acids also activate. each enzyme has limited substrate specificity yet each hydrolyzes p-glycolate and ethyl-p with the same maximal velocity. l-p-lactate is only a good substrate for the red cell enzyme. with both enzymes initial rate da ... | 1986 | 3015949 |
| reaction of phosphofructokinase 2/fructose 2,6-bisphosphatase with monoclonal antibodies. a proof of the bifunctionality of the enzyme. | monoclonal antibodies were derived from mice immunized against homogeneous chicken liver phosphofructokinase 2/fructose 2,6-bisphosphatase. of 112 clones, 30 were found to secrete antibodies that specifically reacted with the antigen in enzyme-linked immunoabsorbant assay (elisa) while 17, which were elisa-negative, produced antibodies that affected the enzymic activity of the antigen. four clones were subcloned and used for an extensive investigation of the reaction of the corresponding antibod ... | 1986 | 3019689 |
| ferredoxin-thioredoxin reductase, an iron-sulfur enzyme linking light to enzyme regulation in oxygenic photosynthesis: purification and properties of the enzyme from c3, c4, and cyanobacterial species. | ferredoxin-thioredoxin reductase (ftr), an enzyme involved in the light regulation of chloroplast enzymes, was purified to homogeneity from leaves of spinach (a c3 plant) and corn (a c4 plant) and from cells of a cyanobacterium (nostoc muscorum). the enzyme is a yellowish brown iron-sulfur protein, containing four nonheme iron and labile sulfide groups, that catalyzes the activation of nadp-malate dehydrogenase and fructose 1,6-bisphosphatase in the presence of ferredoxin and of thioredoxin m an ... | 1987 | 3028266 |
| 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 |
| calmodulin: localization in plant tissues. | calmodulin was purified from bovine brain by preparative sds-polyacrylamide gel electrophoresis. the denatured, purified calmodulin was used to immunize rabbits to produce antiserum. this antiserum was used to study the distribution of calmodulin in plant tissues by indirect immunohistochemistry. the root tips from corn seeds, oat seeds, peanuts, spaghetti squash seeds, and the terminal buds of spinach were investigated. a method for plant tissue sectioning and inhibition of endogenous peroxide ... | 1986 | 3084624 |
| nonessentiality of histidine 291 of rhodospirillum rubrum ribulose-bisphosphate carboxylase/oxygenase as determined by site-directed mutagenesis. | chemical modification of spinach ribulosebisphosphate carboxylase/oxygenase by diethyl pyrocarbonate led to the conclusion that his-298 is an essential active-site residue (igarashi, y., mcfadden, b. a., and el-gul, t. (1985) biochemistry 24, 3957-3962). from the ph dependence of inactivation, the pka of his-298 was observed to be approximately 6.8, and it was suggested that this histidine might be the essential base that initiates catalysis (paech, c. (1985) biochemistry 24, 3194-3199). to expl ... | 1986 | 3090029 |
| computerized semiautomated microbiological assay of folacin. | a semiautomated microbiological folacin assay system is described. a microcomputer controls sample dilutions, medium addition, turbidity determination, and data acquisition. assay capacity is 600 tubes per day, approximately twice that of comparable manual assays. using the automated equipment, more samples can be compared within one assay, eliminating many sources of between-assay variation in large studies. additional advantages of this system are reduced human errors, flexibility of assay des ... | 1986 | 3095308 |
| complete structure of the hydrophilic domain in the porcine nadph-cytochrome p-450 reductase. | the 622-residue amino acid sequence of the hydrophilic domain in the porcine nadph-cytochrome p-450 reductase (ec 1.6.2.4) is reported. the structural data required to complete the sequences published previously [vogel, kaiser, witt & lumper (1985) biol. chem. hoppe-seyler 366, 577-587] and to establish the primary structure of the porcine hydrophilic domain have been obtained by sequencing proteolytic subfragments derived from cnbr fragments and by characterizing the overlapping s-[14c]methylme ... | 1986 | 3098240 |
| molecular cloning and sequencing of a cdna encoding the acyl carrier protein and its flanking domains in the mammalian fatty acid synthetase. | cloned cdnas containing coding sequences for domains proximal to the carboxy terminus of the rat fatty acid synthetase have been isolated using an expression vector and domain-specific antibodies. the coding regions were assigned to specific domains of the multifunctional complex by identification of sequences coding for characterized peptide fragments and by recognition of sequences homologous to other monofunctional enzymes. two clones contain the entire coding region for the acyl carrier prot ... | 1987 | 3109907 |
| purification and characterization of pyruvate:nadp+ oxidoreductase in euglena gracilis. | pyruvate:nadp+ oxidoreductase was homogeneously purified from crude extract of euglena gracilis. the mr of the enzyme was estimated to be 309,000 by gel filtration. the enzyme migrated as a single protein band with mr of 166,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, suggesting that the enzyme consists of two identical polypeptides. the absorption spectrum of the native enzyme exhibited maxima at 278, 380, and 430 nm, and a broad shoulder was observed around 480 nm; the ma ... | 1987 | 3110154 |
| comparative study of specific alpha-1,2-glucosidase activity toward glucosyl galactosyl hydroxylysine in various animal species. | 1. assay of the activity of alpha-1,2-glucosidase was completed within 10 min using reversed-phase high performance liquid chromatography and purified dansylated glucosyl galactosyl hydroxylysine as the substrate. 2. a comparative study was made on the enzyme activity of liver homogenate from eight animal species, mouse, frog, chicken, rabbit, pig, rat, human, bovine and that of a spinach leaf homogenate. alpha-1,2-glucosidase activity in human and bovine liver was very low, and that of alpha-1, ... | 1987 | 3119282 |
| nucleotide sequence of the gene from the cyanobacterium anacystis nidulans r2 encoding the mn-stabilizing protein involved in photosystem ii water oxidation. | the gene for the mn-stabilizing protein (msp; the so-called extrinsic 33-kda protein) that is involved in photosystem ii water oxidation was cloned and sequenced from the genome of the cyanobacterium anacystis nidulans r2. the gene (here designated woxa) was shown to be present in a single copy. the deduced amino acid sequence indicated that the translation product consisted of 277 amino acid residues with a mr of 29,306. the comparison of the sequence with that of mature msp from spinach chloro ... | 1987 | 3120187 |
| reduction and spectroscopic properties of hemoglobins m. | reduction of five hemoglobins m (hbs m) was studied using three enzymatic reducing systems; namely nadph-flavin reductase from human erythrocytes, nadh-cytochrome b5 reductase from human erythrocytes and ferredoxin-nadp reductase from spinach. under anaerobic conditions, abnormal chains in hb m saskatoon were reduced by all three systems, whereas those in hb m milwaukee were reduced by the latter two enzyme systems only. the abnormal chains in hb m hyde park were reduced only by the ferredoxin-n ... | 1987 | 3120482 |
| 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 |
| abortive and productive elongation catalysed by purified spinach chloroplast rna polymerase. | experimental conditions are reported under which purified spinach chloroplast rna polymerase catalyses the abortive elongation reaction on a synthetic poly[d(a-t)] template. the reaction only occurs under very stringent conditions and absolutely requires mn2+ as the metal activator. no reaction can be detected in the presence of mg2+. furthermore, the rate of abortive elongation with the chloroplast enzyme is extremely sensitive to the presence of added salts, such as kcl or (nh4)2so4, in the re ... | 1987 | 3297691 |
| synthesis, cloning, and expression in escherichia coli of a spinach acyl carrier protein-i gene. | a synthetic gene of 268 bp encoding the 82 amino acid spinach acyl carrier protein (acp)-i was constructed based on the known amino acid sequence. two gene fragments, one encoding the amino-terminal portion and the other the carboxy-terminal portion of the protein, were assembled from synthetic oligonucleotides and inserted into the phage m13mp19. these partial gene constructions were joined and inserted into the plasmid ptz19r. dna sequencing confirmed the accuracy of the constructions. the syn ... | 1987 | 3300555 |
| the primary structure of rat ribosomal protein s12. the relationship of rat s12 to other ribosomal proteins and a correlation of the amino acid sequences of rat and yeast ribosomal proteins. | the covalent structure of the rat 40 s ribosomal subunit protein s12 was determined from the sequence of amino acids in tryptic, chymotryptic, thermolytic, and cyanogen bromide peptides and inferred from the sequence of nucleotides in a recombinant cdna. rat ribosomal protein s12 contains 129 amino acids and has a molecular weight of 14,120. the amino acid sequences of a number of ribosomal proteins appear to be related to rat s12. these include spinach chloroplast l7, escherichia coli s5, nicot ... | 1987 | 3308890 |
| the gene for the 9 kd polypeptide, a possible apoprotein for the iron-sulfur centers a and b of the photosystem i complex, in tobacco chloroplast dna. | the gene for the 9 kd polypeptide (a possible apoprotein for the iron-sulfur centers a and b) of photosystem i has been located in the small single-copy region of tobacco chloroplast dna. this gene (psac) was identified by comparing the n-terminal amino acid sequence of the spinach 9 kd polypeptide with the entire sequence of tobacco chloroplast genome. the gene organization is ndhe (101 codons)--263 bp spacer--psac (81 codons)--94 bp spacer--ndhd (509 codons). northern blot hybridization reveal ... | 1987 | 3329576 |
| 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 |
| additives for immobilized ph gradient two-dimensional separation of particulate material: comparison between commercial and new synthetic detergents. | we describe the synthesis of two detergents, l and a15, whose performances as solubilizing agents and as additives in the first-dimension step of a two-dimensional separation are compared with those of some commercial compounds, i.e., nonidet p-40, 3-[(3-cholamidopropyl)dimethylammonio]propanesulfonate(chaps), and sulfobetaine, on three membrane protein preparations: rat rbc ghosts, beef kidney microvilli, and spinach thylakoids. l is 3-]3-dodecylamidoprophylcbdimethylammonio propane-1-sulfonate ... | 1987 | 3425894 |
| hydrogen bonding of sulfur ligands in blue copper and iron-sulfur proteins: detection by resonance raman spectroscopy. | the resonance raman spectrum of the blue copper protein azurin from alcaligenes denitrificans exhibits nine vibrational modes between 330 and 460 cm-1, seven of which shift 0.4-3.0 cm-1 to lower energy after incubation of the protein in d2o. these deuterium-dependent shifts have been previously ascribed to exchangeable protons on imidazole ligands [nestor, l., larrabee, j. a., woolery, g., reinhammar, b., & spiro, t. g. (1984) biochemistry 23, 1084] or to exchangeable protons on amide groups whi ... | 1987 | 3442645 |
| isolation of the catalytically competent small subunit of ribulose bisphosphate carboxylase/oxygenase from spinach under an extremely alkaline condition. | a method for isolating the small subunit (b) of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) from spinach leaf using an alkaline buffer (ph 11.2) in combination with sucrose gradient centrifugation is described. although the yield of isolated subunit b (ca. 20%) was comparable to that previously described (ca. 25%) using the acid precipitation method [andrews, t.j. and lorimer, g.h. (1985) j. biol. chem. 260: 4632-4636], the isolated subunit b in this report suffered less denaturati ... | 1986 | 3461783 |
| encapsulation of adriamycin in human erythrocytes. | adriamycin (doxorubicin) was encapsulated in human erythrocytes by means of a dialysis technique involving transient hypotonic hemolysis followed by isotonic resealing. up to 1.6 mg of the drug was entrapped per ml of packed erythrocytes, with the efficiency of encapsulation being 60-80%. in vitro incubation of the adriamycin-loaded erythrocytes in autologous plasma was accompanied by progressive release of unaltered adriamycin in the medium. the efflux was still evident after 50 hr. the metabol ... | 1986 | 3462740 |
| chloroplasts of higher plants synthesize l-phenylalanine via l-arogenate. | the specific enzymological route of l-phenylalanine biosynthesis has not been established in any higher plant system. the possible pathway routes that have been identified in microorganisms utilize either phenylpyruvate or l-arogenate as a unique intermediate. we now report the presence of arogenate dehydratase (which converts l-arogenate to l-phenylalanine) in cultured-cell populations of nicotiana silvestris. prephenate dehydratase (which converts prephenate to phenylpyruvate) was not detected ... | 1986 | 3463961 |
| further characterization and amino acid sequence of m-type thioredoxins from spinach chloroplasts. | the complete primary structure of m-type thioredoxin from spinach chloroplasts has been sequenced by conventional sequencing including fragmentation, edman degradation and carboxypeptidase digestion. as already reported [tsugita, a., maeda, k. & schürmann, p. (1983) biochem. biophys. res. commun. 115, 1-7] these thioredoxins contain the same active-site sequence as thioredoxins from other sources. based on the amino acid sequence thioredoxin mc contains 103 residues, has a relative molecular mas ... | 1986 | 3510868 |