scholarly journals Tissue and subcellular distribution of the lectin from Datura stramonium (thorn apple)

1979 ◽  
Vol 184 (2) ◽  
pp. 215-219 ◽  
Author(s):  
D C Kilpatrick ◽  
M M Yeoman ◽  
A R Gould
Keyword(s):  
Cell Walls ◽  
Specific Activity ◽  
Soluble Fraction ◽  
Protein Body ◽  
Datura Stramonium ◽  
Immunofluorescent Staining ◽  
Lectin Activity ◽  
Thorn Apple ◽  
Mature Seeds ◽  
Homogenization Medium

Plants of Datura stramonium (thorn-apple) were dissected into their component tissues and examined for the presence of the Datura lectin. This lectin was easily detected in seeds and in various parts of the flowers of adult plants. Traces were also found in green (emerged) cotyledons and roots of seedlings. The specific lectin activity in seeds contained within the fruits increased as the seeds matured. Mature seeds were homogenized in sucrose and separated by differential centrifugation into four fractions, three of which were clearly of distinct composition. Most of the lectin activity sedimented with the low-speed (cell-wall/protein-body) pellet, but a similar specific activity was recovered from the other fractions. However, if EDTA was included in the homogenization medium, three or four times more lectin activity was recovered in the soluble fraction. Immunofluorescent staining of formaldehyde-fixed sections showed that the lectin was localized in the cytoplasm, with little associated with cell walls. The possible relevance of these results to the function of the lectin in plant cells is discussed.

Allelopathic potential of Datura stramonium L. (Thorn-apple)

Weed Research ◽  
1981 ◽  
Vol 21 (3-4) ◽  
pp. 165-170 ◽  
Author(s):  
J. V. LOVETT ◽  
JUDY LEVITT ◽  
A. M. DUFFIELD ◽  
N.G. SMITH
Keyword(s):  
Datura Stramonium ◽  
Allelopathic Potential ◽  
Thorn Apple

scholarly journals Activation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in homogenates of developing rat brain

1979 ◽  
Vol 182 (2) ◽  
pp. 367-370 ◽  
Author(s):  
W A Maltese ◽  
J J Volpe
Keyword(s):  
Rat Brain ◽  
Cholesterol Synthesis ◽  
Specific Activity ◽  
Postnatal Period ◽  
Developing Brain ◽  
Brain Maturation ◽  
Assay Mixture ◽  
Coa Reductase ◽  
Developing Rat ◽  
Homogenization Medium

The specific activity of 3-hydroxy-3-methylglutaryl-CoA reductase increases when homogenates of developing rat brain are incubated at 37 degrees C or kept on ice. This increase is completely blocked by the addition of F- to the homogenization medium and the assay mixture. The capacity for activation of the reductase is greatest during the early postnatal period and declines as brain maturation proceeds. The data suggest that catalytic modification of the reductase may play a role in the regulation of cholesterol synthesis in the developing brain.

scholarly journals STUDIES OF PHOSPHORUS METABOLISM IN MAN: II. A STUDY OF THE PERMEABILITY OF THE HUMAN ERYTHROCYTE TO INORGANIC PHOSPHATE IN VITRO BY THE USE OF RADIOACTIVE PHOSPHATE (P32)

Blood ◽  
1948 ◽  
Vol 3 (12) ◽  
pp. 1472-1477 ◽  
Author(s):  
F. H. L. TAYLOR ◽  
S. M. LEVENSON ◽  
M. A. ADAMS ◽  
MARY KENDRICK
Keyword(s):  
Human Erythrocyte ◽  
Inorganic Phosphate ◽  
Sodium Phosphate ◽  
Specific Activity ◽  
Soluble Fraction ◽  
High Specific Activity ◽  
Phosphorus Metabolism ◽  
Phosphate Exchange ◽  
Inorganic Fraction

Abstract 1. Phosphate exchange in red cells and plasma was studied in vitro using P32 in the form of sodium phosphate as a tracer. 2. No phosphate was added other than the isotopic preparation which was of high specific activity. 3. Inorganic phosphate exchanged freely between the plasma and the erythrocytes at 37.5 C. in a period of four hours. Minimal transfer occurred at 7 C. 4. Most of the added P32 which passed into the erythrocytes during this time remained in the inorganic fraction, less than 15 per cent being found in the organic acid soluble fraction. 5. The specific activity of the inorganic phosphate of the erythrocytes was equal to or greater than that obtaining for the inorganic phosphate of the plasma at the end of the four hour incubation period at 37.5 C.

THE LOCALIZATION AND PROPERTIES OF AN AMINOPEPTIDASE IN ESCHERICHIA COLI B

1963 ◽  
Vol 41 (1) ◽  
pp. 9-18 ◽  
Author(s):  
A. T. Matheson
Keyword(s):  
Membrane Fraction ◽  
Specific Activity ◽  
Soluble Fraction ◽  
Progressive Increase ◽  
Aminopeptidase Activity ◽  
Peptidase Activity ◽  
Phase Growth ◽  
Latent Form ◽  
E Coli ◽  
Escherichia Coli B

Two types of intracellular aminopeptidase activity are present in E. coli B. One type, present in the 'soluble' fraction, is completely inactivated by chymotrypsin or trypsin; the other, in the particulate fractions ('ribosome' and 'membrane'), is resistant to these enzymes. The 'ribosomal' peptidase activity is present partially in a latent form which becomes activated on disruption of the ribosome structure. During the transition from log phase to post-log phase growth there is a progressive increase in the specific activity of the peptidase in the 'soluble' and 'membrane' fraction and a corresponding decrease in the 'ribosome' fraction.

The development of the aleurone layer in canola (Brassica napus)

1993 ◽  
Vol 71 (9) ◽  
pp. 1193-1201 ◽  
Author(s):  
Edwin P. Groot ◽  
Lawrence A. Van Caeseele
Keyword(s):  
Image Analysis ◽  
Electron Microscope ◽  
Brassica Napus ◽  
Cell Walls ◽  
Cell Layer ◽  
Aleurone Layer ◽  
Electron Microscopic ◽  
Aleurone Cells ◽  
Mature Seeds ◽  
Microscopic Techniques

The presence of the aleurone layer in developing seeds of Brassica napus becomes apparent about 22 days after pollination when examined with light and electron microscopic techniques. Prior to aleurone differentiation, the endosperm cellularizes centripetally to form characteristic columns of cells. The pigmented cell layer of the inner integument, which is present in dark-hulled seeds of Brassica, is just external to the aleurone. The first characteristic structures that become apparent inside the aleurone are spherosomes formed by the coalescence of small oil droplets. Shortly thereafter, the cell walls of the aleurone become markedly thickened relative to the surrounding cells. The aleurone cells of mature seeds contain lipid and protein reserves but lack starch. Development of the aleurone layer occurs first near the adaxial area and proceeds until the micropylar area finally differentiates. Endosperm chloroplasts have a characteristic lens shape when viewed in section with the electron microscope. They appear to congregate around a nucleus along with a small amount of cytoplasm causing an astroid-shaped aggregation of cytoplasm in the majority of endosperm cells but only transiently in the aleurone. DNA fluorometry and image analysis showed that aleurone nuclei are triploid; therefore the aleurone layer is derived from the endosperm. Key words: aleurone layer, endosperm, seed development, ploidy, anatomy, Brassica napus.

scholarly journals Properties and developmental regulation of an α-d-galactosidase from Dictyostelium discoideum

1976 ◽  
Vol 158 (2) ◽  
pp. 409-417 ◽  
Author(s):  
D C Kilpatrick ◽  
J L Stirling
Keyword(s):  
Protein Synthesis ◽  
Dictyostelium Discoideum ◽  
Early Development ◽  
Subcellular Distribution ◽  
De Novo ◽  
Specific Activity ◽  
Soluble Fraction ◽  
Developmental Regulation ◽  
Cellular Slime Mould ◽  
Cellular Slime

An alpha-D-galactosidase was detected in cells of the cellular slime mould, Dictyostelium discoideum, at all stages of development. Its specific activity was highest during early development (interphase), and this accumulation of enzyme appears to require protein synthesis de novo. Its subcellular distribution differs from that of other D. discoideum glycosidases, since most activity was recovered in the soluble fraction. No evidence was obtained for more than one isoenzymic form after subjection of extracts to electrophoresis and various chromatographic procedures. It is excreted from the cell during development, but no evidence was found for an extracellular function for the enzyme.

Galactomannan content and key enzymes of its metabolism in seedsof cluster bean [Cyamopsis tetragonoloba (L.) Taub.]

2016 ◽  
Author(s):  
Neha Wadhwa ◽  
Udai Narayan Joshi
Keyword(s):  
Guar Gum ◽  
Specific Activity ◽  
Genetic Manipulation ◽  
Sharp Decrease ◽  
Cyamopsis Tetragonoloba ◽  
Key Enzymes ◽  
Cluster Bean ◽  
Activity Of Enzymes ◽  
The Mean ◽  
Mature Seeds

The present investigation was carried out to estimate galactomannan content in mature seeds of 17 guar genotypes and activity of enzymes involved in galactomannan metabolism. Galactomannan content was found in the range of 16.82 (in IC 310630) to 36.68 per cent (in HG 3-2). The developing pods were sampled at 25, 32, 39 and 46 days after flowering (DAF) for a-galactosyltransferase, ß-D-mannosidase & ß-1, 4-mannanase assay. The mean a-galactosyltransferase specific activity increased from 25 to 39 DAF (1557 to 3093 units) followed by decrease at 46 DAF (1484 units). The mean specific activity increased from 392 to 3166 units with the increase in galactomannan content from 16.82 to 36.68 per cent. Thus, this enzyme showed highly positive correlation with the galactomannan content. The mean specific activity of ß-D-mannosidase increased gradually from 25 to 39 DAF (67 to 138 units) followed by sharp decrease at 46 DAF (32 units). The mean specific activity of ß-1, 4-mannanase was found maximum at 25 DAF (102 units) and afterwards, it decreased continuously with advancement of days after flowering up to 46 days (9 units). On the whole, it can be said that the ß-D-mannosidase requires prior activity of ß-1, 4-mannanase for galactomannan catabolism while a-galactosyltransferase activity is positively correlated with galactomannan content and play a major role in guar gum synthesis and can be further used for gum improvement via genetic manipulation.

scholarly journals Postnatal development of rat lung. Changes in lung lectin, elastin, acetylcholinesterase and other enzymes

1980 ◽  
Vol 188 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Janet T. Powell ◽  
Philip L. Whitney
Keyword(s):  
Lung Development ◽  
Specific Activity ◽  
Neonatal Rat ◽  
Cholinergic Innervation ◽  
Morphological Evidence ◽  
Rat Lung ◽  
Lectin Activity ◽  
Respiratory Organ ◽  
Morphometric Methods ◽  
Glucose 6 Phosphate Dehydrogenase

The development of rat lung from a primitive gas-exchange organ to the mature respiratory organ is in large part a postnatal phenomenon that has been well characterized by morphological and morphometric methods. The alveolarization of the lung is achieved during the first 3 weeks of life. Cholinergic innervation of rat lung also appears postnatally. We have monitored the presence or activity of several proteins during postnatal rat lung development. Newborn-rat lung contains negligible amounts of acetylcholinesterase, but the specific activity of acetylcholinesterase reaches adult values by postnatal day 10–11. Neonatal-rat lung does not contain significant amounts of β-galactoside-binding protein [Powell (1980) Biochem. J.187, 123–129]. The activity of this endogenous lung lectin was apparent at about day 6, was maximal between days 10 and 13 before declining 8–10-fold to reach adult values. Elastin has been implicated from morphological evidence as critical to lung restructuring. We have quantified the amount of desmosine and isodesmosine per g wet wt. of lung. The concentration of elastin, by this criterion, was low and stationary until postnatal day 7; a dramatic increase in elastin concentration occurred between days 10 and 20, when adult values were reached. The peak of lung-lectin activity was coincident with the maturation of acetylcholinesterase and the beginning of rapid elastin cross-linking. The specific activities of angiotensin-converting enzyme, carbonic anhydrase, choline kinase and glucose 6-phosphate dehydrogenase were also monitored.

Seed ontogeny and endosperm chemical analysis in Smilax polyantha (Smilacaceae)

2012 ◽  
Vol 60 (8) ◽  
pp. 693 ◽  
Author(s):  
Aline Redondo Martins ◽  
Sandra Maria Carmello-Guerreiro ◽  
Marcos Silveira Buckeridge ◽  
Clovis Oliveira Silva ◽  
Beatriz Appezzato-da-Glória
Keyword(s):  
Seed Germination ◽  
Cell Walls ◽  
Folk Medicine ◽  
Vascular Bundles ◽  
Chemical Analyses ◽  
Endosperm Cell ◽  
Brazilian Cerrado ◽  
Chemical Factors ◽  
Histochemical Tests ◽  
Mature Seeds

Smilax polyantha Grisebach is a species native to the Brazilian Cerrado biome and is known as sarsaparilla in folk medicine. Despite its popular use, little is known about the propagation of this species, which is still actively illegally exploited. The present study aims to analyse the seed ontogeny and perform endosperm chemical analyses in S. polyantha to elucidate the structural and chemical factors that could be associated with the low germination rates and structural organisation of the seed. The ovules are orthotropic and bitegmic, have short funicles, single collateral vascular bundles that end in the chalaza, and a hypostasis that is composed of chalazal and nucellar cells. The seed covering is non-multiplicative. In mature seeds, the cellularised endosperm has thick-walled cells, the embryo is small and the tegmen comprises two layers of periclinal elongated cells with a red–orange content, which are covered by a cuticle. Histochemical tests detected the presence of lipids, proteins and polysaccharides in the cellular content of mature seeds. Chemical analyses indicated 46.7% hemicellulose per total weight, 67.3% glucose, 30.7% mannose, 1.9% galactose and an absence of fucose, arabinose and rhamnose. In conclusion, the delayed seed germination in S. polyantha is associated with the seed endosperm cell walls.

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