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crystal structure of korean pine (pinus koraiensis) 7s seed storage protein with copper ligands.the prevalence of food allergy has increased in recent years, and korean pine vicilin is a potential food allergen. we have previously reported the crystallization of korean pine vicilin purified from raw pine nut. here we report the isolation of vicilin mrna and the crystal structure of korean pine vicilin at 2.40 å resolution. the overall structure of pine nut vicilin is similar to the structures of other 7s seed storage proteins and consists of an n-terminal domain and a c-terminal domain. ea ...024328105
bacterial leafspot on hubbard squash. 192617735959
a mottled-leaf character in winter squash; inherited as a dominant mendelian character. 194621015950
effect of blanching and frozen storage on ascorbic acid in baby blue winter squash. 196414133711
[on the soluble proteins in the water from seeds of cucurbita maxima duch]. 19664225958
anthelmintic activity of cucurbita maxima (kaddu) seeds. 19676076370
p protein in the phloem of cucurbita. i. the development of p-protein bodies.light and electron microscopical observations of the cells of the phloem of cucurbita maxima have shown that two distinct types of p-protein bodies are formed: a larger type which arises as fine fibrils and a smaller type which apparently arises as groups of tubules. the tubules of the smaller type of body measure 242 +/- 3.6 (se) a (n = 48) and appear morphologically identical with the p1-protein tubules of nicotiana tabacum l. in some of these p1-protein bodies the tubules are arranged in a re ...19685675415
cucurbitacin b delta 23-reductase from cucurbita maxima. ii. cofactor requirements, enzyme kinetics, substrate specificity and other characteristics. 19684384331
effect of infection by hypomyces solani f. sp. cucurbitac on apparent free space, cell membrane permeability, and respiration of squash hypocotyls.initial symptoms and increases in respiration, apparent free space, and rate of leakage of amino acids occurred concomitantly in squash (cucurbita maxima dcne) hypocotyls infected by hypomyces solani f. sp. cucurbitae snyd. and hans. young, rapidly expanding lesions had greater respiratory rates and apparent free space than comparable tissues from healthy plants.hypocotyl tissues above (1-45 mm) lesions possessed greater endogenous respiratory rates (2-3 times) and lower respiratory quotients th ...196816656953
p protein in the phloem of cucurbita. ii. the p protein of mature sieve elements.during maturation of sieve elements in cucurbita maxima duchesne, the p-protein bodies (slime bodies) usually disperse in the tonoplast-free cell. in some sieve elements the p-protein bodies fail to disperse. the occurrence of dispersal or nondispersal of p-protein bodies can be related to the position of the sieve elements in the stem or petiole. in the sieve elements within the vascular bundle the bodies normally disperse; in the extrafascicular sieve elements the bodies often fail to disperse ...19685664205
fractionation of fatty acids of cucurbita maxima seed oil with urea. 19685641684
cucurbitacin b delta 23-reductase from cucurbita maxima. i. assay methods, isolation and purification. 19685640163
uptake of 3-o-methylglucose by healthy and hypomyces-infected squash hypocotyls.rates of uptake of 3-o-methylglucose (meg) by squash (cucurbita maxima) hypocotyl sections from above lesions caused by hypomyces solani f. sp. cucurbitae, race 1, are 2-fold greater than uptake by comparable tissues from healthy plants. kinetic analyses indicate (i) that a single (constitutive) carrier system, with a michaelis constant (km) of 25 to 30 mm, mediates the transport of meg into healthy hypocotyl cells and (ii) that an additional (inducible) system with a much lower km (ca. 2 mm) is ...196916657201
protein filaments-structural components of the phloem exudate : i. observations with cucurbita and nicotiana.fine structure and chemical composition of the phloem exudate of cucurbita maxima and nicotaiana glauca x suaveolens are investigated. filamentous structures, several microns in length, are identified as structural components of the exudate by means of negative staining and electron microscopy. two types of filaments are described: one form measures nearly 40 å in diameter and shows a beaded appearance with regular spacings of about 50 å; it is termed "elementary filament". the second form has a ...197024497023
[insoluble proteins of gourd seeds (cucurbita maxima duch)]. 19705429060
[soluble proteins of the seed of gourd (cucurbita maxima duch.)]. 19705429059
[spectrophotometric analysis of phytochrome in the embryo of cucurbita pepo and cucurbita maxima].phytochrome detection and △ (△o.d.) measurements were made for the first time in a single embryo of pumpkin or gourd thanks to an apparatus adjusted to the differential spectrophotometer constructed by dr. spruit (wageningen). observed △ (△o.d.) values are comparable with usual values obtained by analysis of several seeds in a cuvette. the differential spectrum obtained has the same characteristics as the spectra of seedlings and seeds which can be found in the present literature. the time cours ...197024499981
the amino acid sequence of cytochrome c from cucurbita maxima l. (pumpkin).the amino acid sequence of pumpkin cytochrome c was determined on 2mumol of protein. some evidence was found for the occurrence of two forms of cytochrome c, whose sequences differed in three positions. pumpkin cytochrome c consists of 111 residues and is homologous with mitochondrial cytochromes c from other plants. experimental details are given in a supplementary paper that has been deposited as supplementary publication sup 50005 at the national lending library for science and technology, bo ...19715131733
proteins of the sieve-tube exudate of cucurbita maxima.sieve-tube exudate which appears on cut surfaces of stems of cucurbita maxima as distinct droplets has been depicted in electron micrographs of longitudinal sections of the phloem. the exudate, which was produced from mature sieve tubes only, contained filaments of p-protein, but no mitochondria or vesicles of endoplasmic reticulum. the water-soluble part of the exudate contained at least 12 proteins, as shown by disc-electrophoresis. enzymic activity was found for peroxidases, acid phosphatases ...197124488194
molecular weights of cucurbita sieve tube proteins.by means of sds-polyacrylamide-gel electrophoresis, molecular weights of 15000, 28000, 59000, 116000 and 220000 were determined for the main sieve tube proteins from cucurbita maxima.197124487555
artificial tetraploids of squash (cucurbita maxima duch.). 19715163382
p-protein distribution in mature sieve elements of cucurbita maxima.portions of the hypocotyls of 16-day-old cucurbita maxima plants, from which the cotyledons and first foliage leaves had been removed 2 days earlier, were fixed in glutaraldehyde and postfixed in osmium tetroxide for electron microscopy. in well over 90% of the mature sieve elements examined the p-protein was entirely parietal in distribution in both the lumina and sieve-plate pores. in addition to the parietal p-protein, the unoccluded sieve-plate pores were lined by narrow callose cylinders an ...197224474154
adenosine triphosphatase in the phloem of cucurbita.the distribution of adenosine triphosphatase (atpase) activity in the phloem of petioles and minor veins of cucurbita maxima has been studied using a lead phosphate precipitation procedure. atpase activity was localized in sieve elements, companion cells and parenchyma cells. activity was found at the cell surfaces, associated with the dispersed p-protein of mature sieve elements, in mitochondria, sieve-element reticulum, and at specific regions of the cell walls. it is suggested that the atpase ...197324474397
structure and biochemistry of phloem-proteins isolated from cucurbita maxima. 19744210435
sieve-tube proteins from cucurbita maxima.the two main proteins from the phloem exudate of cucurbita maxima duchesne have been isolated by ammonium-sulfate precipitation, deae-cellulose chromatography, and gel filtration, and have been characterized. they comprise about 40% each of the total protein. the amino-acid composition of these two proteins has been determined. both are highly basic with an iep above 9.5. the smaller protein has a molecular weight of ca. 30000 as determined by analytical ultracentrifugation, gel filtration, and ...197424442451
the biosynthesis of a c19-gibberellin from mevalonic acid in a cell-free system from a higher plant.incubation of a cell-free system from immature seeds of cucurbita maxima duch. with [(14)c]ga12-aldehyde derived from [(14)c]mevalonic acid in the same system yielded the c19-gibberellin, [(14)c]ga4, in addition to the c20-gibberellins, [(14)c]ga37, [(14)c]ga13 and [(14)c]ga43. (ga-gibberellin).197424442706
changes in the cotyledons of cucurbita maxima during germination. v. the nuclear envelope. 19751152111
protein body composition in cuburbita maxima cotyledons as determined by energy dispersive x-ray analysis.energy dispersive x-ray analysis was used to study the composition of certain protein body components in cucurbita maxima cotyledons. the globoid crystal was rich in phosphorus, potassium, and magnesium. this elemental composition provides further evidence that the globoid crystal in squash cotyledon protein bodies is composed of phytin, a myoinositol hexaphosphoric acid salt of potassium and magnesium. calcium, a common component of phytin in many species, was absent or present in only trace am ...197516659190
filament formation in vitro of a sieve tube protein from cucurbita maxima and cucurbita pepo.phloem proteins of the sieve tube exudate from cucurbita maxima duch. and cucurbita pepo l. were investigated as to their filament forming ability in vitro. from the two main proteins (116000 dalton, 30000 dalton) only the 116000 dalton protein was found to form reversibly distinct filaments of 6-7 nm diameter upon removal of sh-protecting agents from the buffer, whereas the 30000 dalton protein was precipitated as amorphous material under these conditions. the protein filaments were similar to ...197524430373
a re-examination of the reputed control of cotyledonary metabolism by the axis.a re-examination has been made of the supposed regulation by the axis of cotyledonary isocitrate lyase (ec 4.1.3.1) activity in cucumis sativas l. and cucurbita maxima duch. and greening in cucumis. when precautions are taken to ensure that isolated cotyledons and cotyledons attached to the axis have equal access to oxygen and/or water no axis effects can be observed. the results underline the importance of maintaining excised plant parts in comparable physical conditions if meaningful physiolog ...197624425000
synthesis of p-protein in mature phloem of cucurbita maxima.cotyledons of cucurbita maxima duch. seedlings were provided with (14)c-labeled amino acids for 12 h. besides the bulk of labeled amino acids the sieve-tube exudate also carried labeled proteins. 80% of the incorporated radioactivity was found in the p-protein, 20% in a neutral protein, and traces were found in acidic proteins after fractionation on diethyl-aminoethyl cellulose columns. the radioactive elutes were characterized by autoradiographs of both disc- and sodium dodecyl sulfate-gelelect ...197624424987
the heterogeneity of phloem exudate proteins from different plants: a comparative survey of ten plants using polyacrylamide gel electrophoresis.proteins in sieve tube exudate from ricinus communis l., acer pseudoplatanus l., aesculus hippocastanum l., cucumis melo l., and two cultivars each of cucumis sativus l., cucurbita pepo l. and cucurbita maxima duchesne were fractionated and compared using polyacrylamide gel electrophoresis. striking differences in major exudate proteins were displayed among the genera and species examined. even cultivars within a single species, although showing general similarities, differed in some prominent p ...197624424985
a comparative analysis of phloem exudate proteins from cucumis melo, cucumis sativus and cucurbita maxima by polyacrylamide gel electrophoresis and isoelectric focusing.proteins in sieve tube exudate from cucumis melo l., cucumis sativus l. and cucurbita maxima duch. were analysed by gel electrophoresis and isoelectric focusing. estimated molecular weights and isoelectric points for the major and minor proteins from each plant species are presented. electrophoresis revealed striking differences between the protein complements of exudatc from the two genera investigated. similarly, although a few exudate proteins from the two species of cucumis possessed identic ...197624424601
correlation between oxygen availability, energy charge, and protein synthesis in squash cotyledons isolated from germinating seeds.the influence of o(2) availability on the rate of protein synthesis, the levels of rna and of adenylates, and the value of the energy charge in squash (cucurbita maxima) cotyledons isolated from seeds germinated for 15 or 28 hours at different o(2) concentration (3% or 20% o(2)) has been investigated.the rate of protein synthesis is five times lower in cotyledons maintained in 3% o(2) than in those maintained in 20% o(2). also net rna synthesis is almost blocked in 3% o(2), while in 20% o(2) it ...197816660244
energy-dispersive x-ray analysis of phosphorus, potassium, magnesium, and calcium in globoid crystals in protein bodies from different regions of cucurbita maxima embryos.the seeds of cucurbita maxima contain protein bodies with electrondense globoid crystals. because of their density globoid crystals are ideal material for energy-dispersive x-ray (edx) analysis studies of elemental composition. fixation trials were carried out to test globoid crystal extraction during glutaraldehyde fixation, water washing, and ethanol dehydration. glutaraldehyde fixation without subsequent washing or dehydration alone produced no significant changes in elemental composition of ...197816660439
peroxidases do not move in phloem.phloem exudates from grafts between queensland blue pumpkin (cucurbita maxima duch.) and candy red hawkesbury watermelon (citrullus vulgaris schrad.) were analysed by iso-electric focusing to detect iso-enzymes of peroxidase. these enzymes did not move in intact phloem but, when stems were cut, they surged rapidly through graft unions.197824413951
the isolation and some properties of a lectin (haemagglutinin) from cucurbita phloem exudate.the occurrence of high haemagglutinating (lectin) activity in phloem exudate from three cucurbit species is reported. the protein responsible for this lectin activity in cucurbita maxima duch. has been isolated by cation exchange chromatography on sepharose and identified by gel electrophoresis. the lectin showed agglutinating activity at concentrations as low as 0.1 μg/ml. no sugar, including those transported in the phloem of these species, interacted with agglutination. the lectin could not b ...197824408004
calcium distribution in globoid crystals of cucurbita cotyledon protein bodies.energy-dispersive x-ray analysis was used to investigate the location of globoid crystals with relatively high ca levels within cotyledons of cucurbita maxima, cucurbita mixta, and cucurbita andreana. the small globoid crystals in both upper and lower epidermal cells commonly contained ca. ca was present in globoid crystals of all provascular regions with the exception of the very small provascular regions of c. maxima. in c. maxima and c. mixta cotyledons, some cases were observed where ca was ...197916660825
isolation and partial amino acid sequence of the trypsin inhibitor from the seeds of cucurbita maxima.trypsin inhibitor from squash (cucurbita maxima) seed was extracted with 0.1 m-acetate buffer, ph 4.5, purified on immobilized trypsin, and separated by se-sephadex c-50 chromatography into three active fractions. all of them inhibited trypsin to the same extent, showed no antichymotrypsin or antikallikrein activity, had a similar molecular weight (about 3300), and contained no tryptophan, phenylalanine or threonine. the partial amino acid sequence of tryptic and peptic peptides of fraction iii ...19806791422
trypsin inhibitor iii from squash seeds (cucurbita maxima), its reactive site and proposed amino acid sequence.the amino acid sequence of trypsin inhibitor iii isolated from squash seeds (cucurbita maxima) was established by edman degradation and standard enzymatic and chemical techniques. the inhibitor consists of 28 amino acids crosslinked by two disulfide bridges. arginine in position 5 was shown to be present at the reactive site of the inhibitor.19817275008
calcium-binding protein in sieve tube exudate.a calcium-binding macromolecule, with an estimated molecular weight greater than 100,000, was detected in phloem exudate from cucurbita maxima and related species. the macromolecule was a component of sieve tube sap, rather than a contaminant leached from cell walls or cut parenchyma cells during exudate collection. the protein nature of this macromolecule was deduced from its size, lability, susceptibility to proteolytic digestion, and by the dependence of calcium-binding activity on thiol-prot ...198124302204
auxin-stimulated atpase in membrane fractions from pumpkin hypocotyls (cucurbita maxima l.).membrane fractions from cucurbita maxima hypocotyls were isolated in a medium which inhibits the action of endogenous phospholipases. after removal of soluble phosphatases by sepharose 2b-cl column chromatography, an auxin-stimulated atpase activity was found in membrane fractions from linear sucrose gradients. in the presence of 10(-4) m phenylacetic acid (paa), the stimulation by indol-3-acetic acid (iaa) exhibited a bimodal concentration dependence with maximal stimulation of about 50% at 10( ...198124302108
effect of pumpkin mosaic virus infection on the hill reaction and primary productivity of pumpkin (cucurbita maxima duch.) leaves. 19826184958
pumpkin seed inhibitor of human factor xiia (activated hageman factor) and bovine trypsin.a strong inhibitor of human hageman factor fragment (hff, beta-factor xiia) and bovine trypsin was isolated from pumpkin (cucurbita maxima) seed extracts by acetone fractionation, by chromatography on columns of diethyl-aminoethylcellulose and carboxylmethyl-sephadex c-25, and by sephadex g-50 gel filtration. pumpkin seed hageman factor inhibitor (phfi) is unusual in its lack of inhibition of several other serine proteinases tested--human plasma, human urinary, and porcine pancreatic kallikreins ...19826215935
subunit structure and interactions of the phloem proteins of cucurbita maxima (pumpkin).the two major proteins from the phloem exudate of cucurbita maxima (pumpkin), pp1 and pp2, were stable in the absence of reducing agents after modification of their accessible cysteine residues with iodoacetamide. this permitted their purification without precautions to prevent oxidation. pp2, a lectin specific for oligomers of n-acetyl-d-glucosamine, was shown by sedimentation-equilibrium ultracentrifugation to be a dimer of mr of 48000. neither dithiothreitol nor tri-(n-acetyl-d-glucosamine) a ...19836884347
purification of squash nadh:nitrate reductase by zinc chelate affinity chromatography.nadh:nitrate reductase (ec 1.6.6.1) was isolated and purified from the green cotyledons of 5-day-old squash seedlings (cucurbita maxima l.). the 10-hour purification procedure consisted of two steps: direct application of crude enzyme to blue sepharose and specific elution with nadh followed by direct application of this effluent to a zn(2+) column with elution by decreasing the ph of the phosphate buffer from 7.0 to 6.2. the high specific activity (100 micromoles per minute per milligram protei ...198316662789
preparation and characteristics of trypsin inhibitors from the seeds of squash (cucurbita maxima) and zucchini (cucurbita pepo var. giromontia).one trypsin inhibitor (i) from zucchini seeds and two (i and iii) from squash seeds were isolated by ammonium sulphate salting out and chromatography on sp-sephadex c-25 and immobilized trypsin. the inhibitors have the same molecular mass, about 3300, contain 29 amino acids, have three disulphide bridges, and lack thr, phe and trp. the isoelectric point of the zucchini inhibitor i and squash inhibitor i is of 5.6, whereas that of the squash inhibitor iii--of 8.3. arg is the n-terminal amino acid ...19836868907
amino-acid sequence of two trypsin isoinhibitors, itd i and itd iii from squash seeds (cucurbita maxima).the amino-acid sequences of two trypsin isoinhibitors, itd i and itd iii, from squash seeds (cucurbita maxima) were determined. both isoinhibitors contain 29 amino-acid residues, including 6 half cystine residues. they differ only by one amino acid. lysine in position 9 of itd iii is substituted by glutamic acid in itd i. arginine in position 5 is present at the reactive site of both isoinhibitors. the previously published sequence of itd iii has been shown to be incorrect.19836840699
biosynthesis of sterols and triterpenoids in tissue cultures of cucurbita maxima.the biosynthesis of sterols and triterpenoids in cucurbita maxima was studied by analysis of unsaponifiable fraction of tissues from different development stages of the plant (seeds, seedlings, adult plant and tissue culture) and by feeding germinating seeds and tissue cultures with [2- (14)c]-acetate. synthesis of cucurbitacins does not occur in callus tissues of cucurbita maxima, whereas a wide variety of 4,4-dimethylsterols present in these tissues testifies of a high level of squaleneoxide c ...198317405044
conversion of gibberellin a20 to gibberellins a 1 and a 5 in a cell-free system from phaseolus vulgaris.the soluble fraction of a cell-free system from immature seeds of phaseolus vulgaris l. converts gibberellin a20 (ga20) to ga1 and ga5. it does however not metabolize ga1 and ga29 to ga5, showing that in this system ga20 is converted directly to ga5. the steps from ga20 to ga1 (3-hydroxylation) and from ga20 to ga5 (δ(2) double-bond formation) require oxygen, fe(2+) and α-ketoglutarate, and are stimulated by ascorbate. the enzymes catalyzing these conversions bate. the enzymes catalyzing these c ...198424254050
subcellular localization of h(+)-atpase from pumpkin hypocotyls (cucurbita maxima l.) by membrane fractionation.a new method of preparing sealed vesicles from membrane fractions of pumpkin hypocotyls in ethanolamine-containing buffers was used to investigate the subcellular localization of h(+)-atpase measured as nigericin-stimulated atpase. in a fluorescence-quench assay, the h(+) pump was directly demonstrated. the h(+) pump was substrate-specific for mg·atp and 0.1 mm diethylstilbestrol completely prevented the development of a δ ph. the presence of unsupecific phosphatase hampered the detection of nig ...198424258584
quaternary structure and composition of squash nadh:nitrate reductase.nadh:nitrate reductase (ec 1.6.6.1) was isolated from squash cotyledons (cucurbita maxima l.) by a combination of blue sepharose and zinc-chelate affinity chromatographies followed by gel filtration on bio-gel a-1.5m. these preparations gave a single protein staining band (mr = 115,000) on sodium dodecyl sulfate gel electrophoresis, indicating that the enzyme is homogeneous. the native mr of nitrate reductase was found to be 230,000, with a minor form of mr = 420,000 also occurring. these result ...19854038708
screening of trichosanthes kirilowii, momordica charantia and cucurbita maxima (family cucurbitaceae) for compounds with antilipolytic activity.saline extracts of trichosanthes kirilowii root tubers and momordica charantia seeds were subjected to differential acetone fractionation. the fraction that precipitated after addition of 0.8 vol. acetone was designated api, the fraction that precipitated after addition of another 1.2 vol. acetone was designated apii, and the fraction that precipitated after addition of another volume acetone was designated apiii. api, apii and apiii are fractions enriched with lectins, abortifacient proteins an ...19854058034
nitrate reductase from squash: cdna cloning and nitrate regulation.the assimilation of nitrate in plants involves the reduction of nitrate to ammonia in two steps. the first step requires nitrate reductase, a nitrate-inducible enzyme. when seedlings of squash (cucurbita maxima l.) were treated with nitrate, both nitrate reductase activity and protein were induced in the cotyledons. poly(a)(+) rna was prepared from cotyledons of nitrate-treated seedlings and was used to construct a lambdagt11 cdna library. using antibodies from mice immunized against purified ni ...198616593773
response of various cucurbits to infection by plasmid-harboring strains of agrobacterium.tumor formation in cucurbit cultivars resulting from infection by various strains of agrobacterium tumefaciens and agrobacterium rhizogenes is environmentally affected. in all instances, tumors could be induced on excised cotyledons while inoculating attached cotyledons or stems resulted in no tumor formation. in addition, buttercup squash (cucurbita maxima duch. buttercup) was most susceptible to tumor formation, while butterbush squash (cucurbita maxima duch. butterbush) failed to form tumors ...198616665082
identification of a volatile attractant for diabrotica and acalymma spp. from blossoms of cucurbita maxima duchesne.fractionation of headspace volatiles from cucurbita maxima blossoms by high-performance liquid chromatography resulted in the isolation of a single component which was highly active in an electroantennogram bioassay on diabrotica undecimpunctata howardi antennae. this compound was identified as indole by gas chromatography-mass spectrometry. field-trapping bioassays were conducted which indicated that indole is a potent attractant of the western corn rootworm,d. virgifera virgifera, and the stri ...198624306908
sterols of cucurbitaceae: the configurations at c-24 of 24-alkyl-δ(5)-,δ(7)- and δ(8)-sterols.the major sterols of the seeds ofbenincasa cerifera, cucumis sativus, cucurbita maxima, c. pepo andtrichosanthes japonica and of the mature plant tissues (leaves and stems) ofcitrullus battich, cucumis sativus andgynostemma pentaphyllum of the family cucurbitaceae were 24-ethyl-δ(7)-sterols which were accompanied by small amounts of saturated and δ(5)-and δ(8)-sterols. the 24-ethyl-δ(7,22),δ(7,25(27)) and δ(7,22,25(27))-sterols constituted the predominant sterols for the seed materials, whereas ...198627519240
induction of elf transmembrane potentials in relation to power-frequency electric field bioeffects in a plant root model system. ii. the effect of 60 hz electric fields on the growth of different regions of the cucurbit root elongation zone.the region of elongation in cucumis sativus and cucurbita maxima roots was marked at increasing distances from the apex to provide an analog of increasing cell size. these roots were exposed/sham-exposed to 60 hz electric fields and the growth rates of the root segments measured. the growth rate effect magnitude varied with increasing distance from the root tip at constant field strength, and with increasing applied field strength. these results provide strong, qualitative support for the postul ...19863763828
induction of elf transmembrane potentials in relation to power-frequency electric field bioeffects in a plant root model system. i. relationship between applied field strength and cucurbitaceous root growth rates.seminal roots of cucumis sativus and cucurbita maxima were exposed to 60 hz electric fields of 100-500 v x m-1 in a conducting aqueous inorganic growth medium. root growth rates were measured to produce a dose-response relationship for each species. the species were selected for study because of their familial relationship, reported sensitivity to 60 hz, 360 v x m-1 electric fields, and differing average root cell sizes. the latter characteristic influences the magnitude of elf membrane potentia ...19863763827
different at-rich satellite dnas in cucurbita pepo and cucurbita maxima.the at-rich highly repeated satellite dna of cucurbita pepo (zucchini) and cucurbita maxima (pumpkin) were cloned and their dna structure was investigated. dna sequencing revealed that the repeat length of satellite dna in cucurbita pepo is 349-352 base pairs. the percentage of at-base pairs is about 61%. this satellite is highly conserved in restriction enzyme pattern and dna sequence; sequence heterogeneity is about 10%. in contrast, the satellite dna of cucurbita maxima has a repeat length of ...198624240758
the loss of carbon-20 in c19-gibberellin biosynthesis in a cell-free system from pisum sativum l.the fate of the carbon-20 atom in gibberellin (ga) biosynthesis was studied in a cell-free system from pisum sativum. this carbon atom is lost at the aldehyde stage of oxidation when c20-gas are converted to c19-gas. gibberellin a12 labeled with (14)c at c-20 was prepared from [3'-(14)c]mevalonic acid with a cell-free system from cucurbita maxima and incubated with the pea system. analysis of the gas and aqueous phases showed that (14)co2 was formed at the same rate and in nearly equivalent amou ...198624232760
allozyme segregation ratios in the interspecific cross cucurbita maximaxc. ecuadorensis suggest that hybrid breakdown is not caused by minor alterations in chromosome structure.the parentals of the interspecific cross cucurbita maxima xc. ecuadorensis had different isozyme phenotypes for 12 enzyme systems. characterization of the systems demonstrated that the expression and intracellular distribution of the isozymes were similar to those in other plant taxa; however, a considerable number of duplicate loci were identified, indicative of a polyploid ancestry for cucurbita. genetic analysis provided evidence for 20 loci segregating in f(2) and backcross populations. five ...198617246350
an improved enzymatic synthesis of labeled gibberellin a12-aldehyde and gibberellin a12.the biochemical synthesis of labeled gibberellin a12-7-aldehyde (ga12ald) and and gibberellin a12 (ga12) from labeled r,s-mevalonic acid (mva) using cell-free extracts from pumpkin (cucurbita maxima) endosperm has been improved over the previously reported procedure. three major improvements were developing a one-step hplc procedure to isolate ga12ald and ga12 in radiochemically pure form; adjusting the ph of the reaction mix to ph 6.9 which increased the ga12ald/ga12 ratio over that at ph 7.8 b ...19863754395
cucurbitacin delta 23-reductase from the fruit of cucurbita maxima var. green hubbard. physicochemical and fluorescence properties and enzyme-ligand interactions.cucurbitacin delta 23-reductase from cucurbita maxima var. green hubbard fruit displays an apparent mr of 32,000, a stokes radius of 263 nm and a diffusion coefficient of 8.93 x 10(-7) cm2 x s-1. the enzyme appears to possess a homogeneous dimeric quaternary structure with a subunit mr of 15,000. two tryptophan and fourteen tyrosine residues per dimer were found. emission spectral properties of the enzyme and fluorescence quenching by iodide indicate the tryptophan residues to be buried within t ...19863707515
immunocytochemical localisation of phloem lectin from cucurbita maxima using peroxidase and colloidal-gold labels.antibodies were raised against lectin purified from the sieve-tube exudate of cucurbita maxima. immunocytochemistry, using peroxidase-labelled antibodies and protein a-colloidal gold, was employed to determine the location of the lectin within the tissues and cells of c. maxima and other cucurbit species. the anti-lectin antibodies bound to p-protein aggregates in sieve elements and companion cells, predominantly in the extrafascicular phloem of c. maxima. this may reflect the low rate of transl ...198724233009
transcription and translation of phloem protein (pp2) during phloem differentiation in cucurbita maxima.the synthesis of a major phloem protein, pp2, was investigated by measurement of the mrna at various stages of phloem development in cucurbita. quantitative assays with immuno-electrophoresis showed that the amounts of pp2 in hypocotyls of cucurbita seedlings increased with the age of seedlings. an increase in mrna for pp2 during the early stages of seedling growth was also observed by immunoprecipitation of the invitro translation products of hypocotyl polyadenylated rna. there was close timing ...198724232970
effects of 60-hz electric fields on cellular elongation and radial expansion growth in cucurbit roots.serial longitudinal and transverse sections were prepared from roots of cucumis sativus and cucurbita maxima that had been exposed/sham-exposed to 60-hz electric fields for 0-2 days. field exposures were selected to produce a 10-20% or a 70-80% growth inhibition in whole roots of both species. cortical cell length and diameter were measured using a microscope and eyepiece micrometer; measurements were conducted "blind." in both species, inhibition of cellular elongation was associated with expos ...19873580000
conversion of xanthoxin to abscisic acid by cell-free preparations from bean leaves.cell-free extracts from the leaves of phaseolus vulgaris l. convert xanthoxin to abscisic acid. the enzyme activity in dialyzed or acetone-precipitated extracts shows a strong dependence on either nad or nadp. the enzyme activity appears to be cytosolic with no significant activity observed in chloroplasts. the activity was observed in extracts from roots of phaseolus vulgaris, and also in extracts prepared from the leaves of pisum sativum l., zea mays l., cucurbita maxima duchesne, and vigna ra ...198716665831
properties of a small basic peptide from pumpkin seeds.a small basic peptide with an unusual amino acid composition has been isolated from the seeds of pumpkin, cucurbita maxima. amino acid analysis and sequence data show the protein to be about 36 residues in length, with an approximate composition lys(1), arg(14), asp(3), (glu + gln)(15), gly(1), pro(1), trp(1). on the basis of composition, the molecular weight is approximately 5000 daltons and the nitrogen content by weight is 20.4%. twelve amino acids are entirely lacking. the peptide is slightl ...198816666381
[obtention and evaluation of a precooked flour of auyama (cucurbita maxima) and rice, enriched with oleaginous proteins and/or skim milk].the purpose of the present study was the production of a precooked blend made of pumpkin squash and rice flour (prb), processed with drum dyer. the blend was supplemented with different protein sources: soy, sesame and deffated milk. the following formulations were obtained: i) prb + 10.5% deffated soy flour; ii) prb + 15% deffated milk; iii) prb + 5% deffated sesame flour + 10% deffated milk; iv) prb + 5% deffated soy flour + 10% deffated sesame flour, and v) prb + 9.5% deffated soy flour + 9.5 ...19883256284
two linear plasmids in mitochondria of fusarium solani f. sp. cucurbitae.two linear plasmid-like dnas designated pfsc1 (9.2 kbp) and pfsc2 (8.3 kbp) were found in an isolate of the plant pathogenic fungus fusarium solani f. sp. cucurbitae race 1. the plasmids were maternally inherited and copurified with mitochondrial dna obtained from a mitochondria-enriched cell fraction suggesting that they are located in mitochondria. the plasmids did not share extensive sequence similarity. no homology was detected between either plasmid and the nuclear or mitochondrial genome w ...19883399553
identification of a dispersed mboi repeat family in five higher plant genomes.digestion of nuclear dnas of five plants, namely cucurbita maxima (red gourd), trichosanthes anguina (snake gourd), cucumis sativus (cucumber), cajanus cajan (pigeon pea) and phaseolus vulgaris (french bean) with the restriction endonuclease mboi yielded discrete size classes with molecular weights in the range of 0.5 to 5 kbp. the mboi digestion pattern of cot 0.1 dna in french bean is comparable with that of total dna, indicating that these bands represented highly repeated dna sequences. clea ...19883233342
iron assimilation in plants: reduction of a ferriphytosiderophore by nadh:nitrate reductase from squash.nadh:nitrate reductase (ec 1.6.6.1) from squash (cucurbita maxima duch., cv. buttercup) can catalyze the reduction of a ferriphytosiderophore from barley (hordeum vulgare l. cv. europa). maximal activity occurs at ph 6, with an apparentk m andv max of 76 μm and 21 nmol·min(-1)·(mg protein)(-1), respectively. the ferriphytosiderophore strongly inhibits nitrate reduction catalyzed by nitrate reductase at the optimal ph for nitrate reduction, i.e. 7.5. on the contrary, nitrate is a poor inhibitor o ...198824226694
synthesis and biological activity of an azido derivative of paclobutrazol, an inhibitor of gibberellin biosynthesis.a photolabile azido derivative of the kaurene oxidase inhibitor 1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-l-yl) pentan-3-ol (paclobutrazol) has been synthesized for use as a photoaffinity labeling agent. the compound was tested as an inhibitor of the oxidation of ent-kaurene catalyzed by cell-free preparations from endosperm of cucurbita maxima. the i(50) of the azido derivative was 9.5 nanomolar, which compares well with that of paclobutrazol (6.3 nanomolar in our measurements). the azid ...198816666477
phytochrome-mediated light regulation of nitrate reductase expression in squash cotyledons.in etiolated squash (cucurbita maxima l.) cotyledons, nitrate-inducible nadh:nitrate reductase activity and protein were increased in darkness by red light pulses with red/far-red photoreversibility. continuous far-red light also led to increased levels of nitrate reductase activity and protein. poly(a)+rna, which hybridizes to squash nitrate reductase cdna, was also increased by light treatments. thus, we found that after nitrate triggering, nitrate reductase expression appears to be regulated ...198816666287
nuclear magnetic resonance solution and x-ray structures of squash trypsin inhibitor exhibit the same conformation of the proteinase binding loop.a comparison of the solution nuclear magnetic resonance (n.m.r.) structures of squash trypsin inhibitor from seeds of the squash cucurbita maxima with the x-ray structure of a trypsin complex of the inhibitor shows that the n.m.r. and x-ray structures are similar in terms of the global folding and secondary structure. the average atomic root-mean-square difference between the 36 n.m.r. structures on the one hand and the x-ray structure is 0.96 a for the backbone atoms and 1.95 a for all heavy at ...19892614838
determination of the complete three-dimensional structure of the trypsin inhibitor from squash seeds in aqueous solution by nuclear magnetic resonance and a combination of distance geometry and dynamical simulated annealing.the complete three-dimensional structure of the trypsin inhibitor from seeds of the squash cucurbita maxima in aqueous solution was determined on the basis of 324 interproton distance constraints, 80 non-nuclear overhauser effect distances, and 22 hydrogen-bonding constraints, supplemented by 27 phi backbone angle constraints derived from nuclear magnetic resonance measurements. the nuclear magnetic resonance input data were converted to the distance constraints in a semiquantitative manner afte ...19892614837
the cucurbita maxima ribosomal dna intergenic spacer has a complex structure.the nucleotide (nt) sequence of the 5508-nt intergenic spacer (igs), between the 25s- and the 18s-coding regions of cucurbita maxima rdna, was determined. the fragment sequenced is 6142 nt long and includes 472 nt of 25s- and 162 nt of 18s-coding regions. the igs has a complex primary structure, composed of five repetitive families (a-e) and three unique domains. it is dominated by the presence of nine, tandemly-repeating units of approximately 250 nt (repeat d), each unit containing four copies ...19892583512
the refined 2.0 a x-ray crystal structure of the complex formed between bovine beta-trypsin and cmti-i, a trypsin inhibitor from squash seeds (cucurbita maxima). topological similarity of the squash seed inhibitors with the carboxypeptidase a inhibitor from potatoes.the stoichiometric complex formed between bovine beta-trypsin and the cucurbita maxima trypsin inhibitor i (cmti-i) was crystallized and its x-ray crystal structure determined using patterson search techniques. its structure has been crystallographically refined to a final r value of 0.152 (6.0-2.0 a). cmti-i is of ellipsoidal shape; it lacks helices or beta-sheets, but consists of turns and connecting short polypeptide stretches. the disulfide pairing is cys-3i-20i, cys-10i-22i and cys-16i-28i. ...19892914611
[characterization of xanthomonas campestris pv. cucurbitae, causal agent of the bacterial spot of squash].bacterial leaf spot of squash was characterized for the first time in argentina. cultural, physiological, morphological and cross-infection tests on cucurbitaceae showed that the pathogen was xanthomonas campestris pv. cucurbitae (bryan) dye. the bacterium isolated from winter squash proved pathogenic for pumpkin, winter squash, cucumber and watermelon but no for muskmelon.19892748850
isolation and serological comparison of virus-coded proteins of three potyviruses infecting cucurbitaceous plants.cylindrical inclusion proteins (cips), amorphous inclusion proteins (aips), and virus particles were partially purified from cucurbita maxima leaves infected with zucchini yellow mosaic virus (zymv), watermelon mosaic virus 2 (wmv2), and the watermelon mosaic virus 1 strain of papaya ringspot virus (prsv-w). antisera to these individual antigens, except aips of zymv and wmv2, were prepared and used to determine with electroblot-elisa the serological differentiation indices (sdis) between homolog ...19902338401
inhibition of human beta-factor xiia by squash family serine proteinase inhibitors.many inhibitors of trypsin and human beta-factor xiia have been isolated from squash and related seeds and sequenced (wieczorek et al., biochem. biophys. res. comm. (1985) 126, 646-652). the association equilibrium constants (ka) of several of these inhibitors have now been determined with human beta-factor xiia using a modification of the method of green and work (park et al., fed. proc. fed. am. soc. exp. biol. (1984) 43, 1962). the ka's range from 7.8 x 10(4) m-1 to 3.3 x 10(8) m-1. two isoin ...19902306254
intact plastids are required for nitrate- and light-induced accumulation of nitrate reductase activity and mrna in squash cotyledons.induction of nitrate reductase activity and mrna by nitrate and light is prevented if chloroplasts are destroyed by photooxidation in norflurazon-treated squash (cucurbita maxima l.) cotyledons. the enzyme activity and mrna can be induced if norflurazon-treated squash seedlings are kept in low-intensity red light, which minimizes photodamage to the plastids. it is concluded that induction of nitrate reductase activity and nitrate reductase mrna requires intact plastids. if squash seedlings grown ...199016667294
a new protein inhibitor of trypsin and activated hageman factor from pumpkin (cucurbita maxima) seeds.a protein inhibitor (cmti-v; mr 7106) of trypsin and activated hageman factor (factor xiia), a serine protease involved in blood coagulation, has been isolated for the first time from pumpkin (cucurbita maxima) seeds by means of trypsin-affinity chromatography and reverse phase high performance liquid chromatography (hplc). the dissociation constants of the inhibitor complexes with trypsin and factor xiia have been determined to be 1.6 x 10(-8) and 4.1 x 10(-8) m, respectively. the primary struc ...19902226848
sugar composition and molecular weight distribution of cell wall polysaccharides in outer and inner tissues from segments of dark grown squash (cucurbita maxima duch.) hypocotyls.the elongation growth of stem segments is determined by the outer cell layers (epidermis and collenchyma). we measured the sugar composition and molecular weight distribution of pectin and hemicellulose fractions obtained from inner and outer tissues of squash (cucurbita maxima duch.) hypocotyls. in addition, we studied the changes in these parameters after a 9 hour period of incubation of the segments. the results show that outer tissues have higher molecular weight pectin and hemicellulose com ...199016667612
heterogeneity and organization of the ribosomal rna genes of cucurbita maxima.thirty-six clones were recovered from cucurbita maxima genomic dna which had been enriched for rdna and cleaved at the unique repeat unit hind iii site. twenty-nine of these, which contain complete rdna units, were compared to a standard whose intergenic spacer (igs) nucleotide sequence has been determined. twenty-one are identical in length and restriction site pattern. eight which differ from the standard in length do so because of addition or deletion of varying numbers of igs subrepetitive u ...19902102876
cloning of a cdna encoding 1-aminocyclopropane-1-carboxylate synthase and expression of its mrna in ripening apple fruit.1-aminocyclopropane-1-carboxylate (acc) synthase (ec 4.4.1.14) purified from apple (malus sylvestris mill.) fruit was subjected to trypsin digestion. following separation by reversed-phase high-pressure liquid chromatography, ten tryptic peptides were sequenced. based on the sequences of three tryptic peptides, three sets of mixed oligonucleotide probes were synthesized and used to screen a plasmid cdna library prepared from poly(a)(+) rna of ripe apple fruit. a 1.5-kb (kilobase) cdna clone whic ...199124186277
differential effect of auxin on molecular weight distributions of xyloglucans in cell walls of outer and inner tissues from segments of dark grown squash (cucurbita maxima duch.) hypocotyls.effects of indole-3-acetic acid (iaa) on the mechanical properties of cell walls and structures of cell wall polysaccharides in outer and inner tissues of segments of dark grown squash (cucurbita maxima duch.) hypocotyls were investigated. iaa induced the elongation of unpeeled, intact segments, but had no effect on the elongation of peeled segments. iaa induced the cell wall loosening in outer tissues as studied by the stress-relaxation analysis but not in inner tissues. iaa-induced changes in ...199116668092
screening of the antimalarial activity of plants of the cucurbitaceae family.crude ethanolic extracts (cees) from two species of cucurbitaceae, cucurbita maxima and momordica charantia (commonly called "abóbora moranga" and "melão de são caetano", respectively) were assayed for antimalarial activity by the 4-d suppressive test. the cee of dry c. maxima seeds showed strong antimalarial activity following oral administration (250 and 500 mg/kg), reducing by 50% the levels of parasitemia in plasmodium berghei-infected mice. treatment of normal animals with 500 mg/kg of the ...19911841996
synthesis of a wild-type and three mutant cucurbita maxima trypsin inhibitor-encoding genes by a single-strand approach.a single-strand approach to gene assembly, based on a modification of an in vitro complementary oligodeoxyribonucleotide template-directed ligation of the desired sequence to a linearized vector [chen et al., nucleic acids res. 18 (1990) 871-878], is described. the gene coding for the wild-type cucurbita maxima trypsin inhibitor of 29 amino acid residues [bode et al., febs lett. 242 (1989) 285-292], as well as three mutant forms of the gene, in which two of the three disulfide bonds have been re ...19911937021
purification of ent-kaurene oxidase from gibberella fujikuroi and cucurbita maxima. 19921397591
effects of 3-methylgibberellin analogs on gibberellin 3β-hydroxylases and plant growth.six 3-methylgibberellin analogs were synthesized, and their effects on the ga 3β-hydroxylases from immature seeds of phaseolus vulgaris and cucurbita maxima, and/or on the growth of dwarf rice (oryza sativa l. cv. tan-ginbozu) and cucumber (cucumis sativus l. cv. spacemaster) were investigated. 3-methyl-ga5 and 2, 3-didehydro-3-methyl-ga9· inhibited the conversion of [2, 3-(3)h2]ga9 to [2-(3)h]ga4 by ga 3β-hydroxylases from both p. vulgaris and c. maxima at 3 μm and higher. their c/d-ring-rearra ...199227286375
homonuclear three-dimensional noe-noe nuclear magnetic resonance/spectra for structure determination of proteins in solution.the solution structures of two proteins (cmti-i, a trypsin inhibitor from cucurbita maxima, and hisactophilin, an actin binding protein of 118 amino acids) have been determined based on the noe data derived solely from the homonuclear 3d noe-noe magnetic resonance spectroscopy. two different approaches for extraction of the structural information from the 3d noe-noe experiment were tested. one approach was based on the transformation of the 3d intensities into distance constraints. in the second ...19921447779
natural abundance 15n nmr assignments delineate structural differences between intact and reactive-site hydrolyzed cucurbita maxima trypsin inhibitor iii.15n nmr assignments were made to the backbone amide nitrogen atoms at natural isotopic abundance of intact and reactive-site (arg5-ile6) hydrolyzed cucurbita maxima trypsin inhibitor iii (cmti-iii and cmti-iii*, respectively) by means of 2d proton-detected heteronuclear single bond chemical shift correlation (hsbc) spectroscopy, utilizing the previously made sequence-specific 1h nmr assignments (krishnamoorthi et al. (1992) biochemistry 31, 898-904). comparison of the 15n chemical shifts of the ...19921618315
structural consequences of the natural substitution, e9k, on reactive-site-hydrolyzed squash (cucurbita maxima) trypsin inhibitor (cmti), as studied by two-dimensional nmr.sequence-specific hydrogen-1 nmr assignments were made to all of the 29 amino acid residues of reactive-site-hydrolyzed cucurbita maxima trypsin inhibitor i (cmti-i*) by the application of two-dimensional nmr (2d nmr) techniques, and its secondary structural elements (two tight turns, a 3(10)-helix, and a triple-stranded beta-sheet) were identified on the basis of short-range noesy cross peaks and deuterium-exchange kinetics. these secondary structural elements are present in the intact inhibito ...19921599921
proton nmr studies of cucurbita maxima trypsin inhibitors: evidence for ph-dependent conformational change and his25-tyr27 interaction.a ph-dependent his25-tyr27 interaction was demonstrated in the case of cucurbita maxima trypsin inhibitors (cmti-i and cmti-iii) by means of nuclear magnetic resonance (nmr) spectroscopy. ph titration, line widths, peak shapes, deuterium exchange kinetics, and two-dimensional nuclear overhauser effect spectroscopy (noesy) were employed to characterize a conformational change involving tyr27, which was shown to be triggered by deprotonation of his25 around ph 6. a hydrogen bond is proposed to be ...19921731947
two-dimensional nmr studies of squash family inhibitors. sequence-specific proton assignments and secondary structure of reactive-site hydrolyzed cucurbita maxima trypsin inhibitor iii.the solution structure of reactive-site hydrolyzed cucurbita maxima trypsin inhibitor iii (cmti-iii*) was investigated by two-dimensional proton nuclear magnetic resonance (2d nmr) spectroscopy. cmti-iii*, prepared by reacting cmti-iii with trypsin which cleaved the arg5-ile6 peptide bond, had the two fragments held together by a disulfide linkage. sequence-specific 1h nmr resonance assignments were made for all the 29 amino acid residues of the protein. the secondary structure of cmti-iii*, as ...19921731946
molecular cloning of an 1-aminocyclopropane-1-carboxylate synthase from senescing carnation flower petals.synthetic oligonucleotides based on the sequence of 1-aminocyclopropane-1-carboxylate (acc) synthase from tomato were used to prime the synthesis and amplification of a 337 bp tomato acc synthase cdna by polymerase chain reaction (pcr). this pcr product was used to screen a cdna library prepared from mrna isolated from senescing carnation flower petals. two cdna clones were isolated which represented the same mrna. the longer of the two clones (caracc3) contained a 1950 bp insert with a single o ...19921731995
glycine-rich analogues of cucurbita maxima trypsin inhibitor (cmti-iii) substituted by valine in position 27 display relatively low antitrypsin activity.five new analogues of the trypsin inhibitor cmti-iii were synthesized by the solid-phase method. all analogues containing a valine residue in position 27 and glycine residues in some or all of the positions 9, 11, 14, 17, 19, 29 as well as in two cases a norleucine residue in position 8 displayed association equilibrium constants by 6-7 orders of magnitude lower than the native cmti-iii inhibitor.19938267878
gibberellin biosynthesis in cell-free extracts from developing cucurbita maxima embryos and the identification of new endogenous gibberellins.gibberellin (ga) biosynthetic pathways from ga12-aldehyde, ga12 and ga53 were investigated in cell-free systems from developing embryos of cucurbita maxima l. gibberellin a12-aldehyde and ga12 were converted to ga25, putative 12α-hydroxyga25, ga13 and ga39 as main products. minor products were ga4, ga34 and, when ga12 was the substrate, putative 12α-hydroxyga12. the intermediates ga15 and ga24 accumulated at low protein concentrations. the influence of various factors on ga12 metabolism was exam ...199324178491
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