Characterization of excretory-secretory antigens of Fasciola hepatica

Parasitology ◽  
1982 ◽  
Vol 85 (1) ◽  
pp. 179-188 ◽  
Author(s):  
D. O. Irving ◽  
M. J. Howell
Keyword(s):  
Molecular Weight ◽  
Culture Medium ◽  
Fasciola Hepatica ◽  
Culture Media ◽  
Minor Component ◽  
Serum Free Medium ◽  
Molecular Weights ◽  
A Minor ◽  
Somatic Antigens

SUMMARYTwenty-one day old Fasciola hepatica were recovered from the livers of infected mice and cultured for 5–7 days in a serum-free medium containing either [C]leucine, [C]isoleucine or [S]methionine, or in a medium containing [C]leucine and serum from a sheep vaccinated with excretory– secretory (ES) antigens of juvenile F. hepatica. All three labelled amino acids were incorporated into fluke proteins. Labelled proteins also appeared in the culture medium. Three major polypeptides detected in the culture media had apparent molecular weights of 26000, 24000 and 23000. All were immunoprecipitated from [C]leucine-labelled culture medium using antisera against fluke somatic antigens raised in rabbits or from sheep vaccinated with ES antigens of juvenile F. hepatica. A polypeptide of molecular weight 27 000 was also prominent in the culture medium when [C]isoleucine was used. This polypeptide was present as a minor component when [C]leucine and [S]methionine were included in the culture media; it did not appear to be immunoprecipitated by the above antisera from [C]leucine-labelled culture medium. In the presence of serum from vaccinated sheep, the ES antigens formed immune complexes which contained the polypeptides mentioned above, together with several higher molecular weight polypeptides. Additionally, a number of minor bands of varying molecular weight were present. After micro-Ouchterlony gel immunodiffusion, 2 precipitin lines formed between the labelled ES antigens and antisera. Electrophoresis of these indicated that the 23000, 24000 and 26000 Dalton labelled polypeptides were present in each. The higher molecular weight and the 27000 Dalton labelled polypeptides were also present in one of the lines.

scholarly journals Sedimentation-equilibrium studies on the heterogeneity of two β-lactamases

1970 ◽  
Vol 118 (3) ◽  
pp. 467-474 ◽  
Author(s):  
P. H. Lloyd ◽  
A. R. Peacocke
Keyword(s):  
Molecular Weight ◽  
Diffusion Coefficients ◽  
Minor Component ◽  
Theoretical Solution ◽  
Sedimentation Equilibrium ◽  
Equilibrium Studies ◽  
Molecular Weights ◽  
A Minor

Solutions of crystalline β-lactamase I and β-lactamase II, prepared by Kuwabara (1970), were examined in the ultracentrifuge and their sedimentation coefficients, diffusion coefficients, molecular weights and heterogeneity determined. Each sample was shown to consist of a major component comprising at least 97% of the material and a minor component of much higher molecular weight. The molecular weights of the major components were 27800 for β-lactamase I and 35600 for β-lactamase II. Emphasis is placed on a straightforward practical way of analysing the sedimentation-equilibrium results on mixtures of two macromolecular components rather than on a strict theoretical solution. Appendices describe the theory of systems at both chemical and sedimentation equilibrium and the procedure for calculating the combined distribution of two components.

scholarly journals Rat liver alcohol dehydrogenase. Purification and properties

1971 ◽  
Vol 125 (4) ◽  
pp. 1039-1047 ◽  
Author(s):  
M J Arslanian ◽  
E Pascoe ◽  
J G Reinhold
Keyword(s):  
Molecular Weight ◽  
Alcohol Dehydrogenase ◽  
Rat Liver ◽  
Gel Filtration ◽  
Rabbit Antiserum ◽  
Minor Component ◽  
Disc Electrophoresis ◽  
Supernatant Fraction ◽  
Liver Alcohol Dehydrogenase ◽  
A Minor

Alcohol dehydrogenase (EC 1.1.1.1) from the rat liver supernatant fraction has been purified 200-fold and partially characterized. The isolation procedure involved ammonium sulphate fractionation, DEAE-Sephadex chromatography and gel filtration. The purified enzyme behaved as a homogeneous preparation as evaluated by cellulose acetate and polyacrylamide-gel disc electrophoresis. Sulphoethyl-Sephadex chromatography and immunoelectrophoresis with rabbit antiserum indicated the presence of a minor component. Rat liver alcohol dehydrogenase appears to contain 4mol of zinc/mol, has an estimated molecular weight of 65000 and consists of two subunits of similar molecular weight. Heavy-metal ions, thiol-blocking reagents, urea at concentrations below 8m, low pH (5.5) and chelating agents deactivate the enzyme but do not dissociate it into subunits. Deactivated enzyme could not be reactivated. The enzyme is strictly specific for NAD+ and has a broad specificity for alcohols, which are bound at a hydrophobic site. Inhibition occurred with the enzyme equilibrated with Zn2+ at concentrations above 0.1mm.

Induction and regulation of connexin26 by glucagon in primary cultures of adult rat hepatocytes

1995 ◽  
Vol 108 (8) ◽  
pp. 2771-2780 ◽  
Author(s):  
T. Kojima ◽  
T. Mitaka ◽  
Y. Shibata ◽  
Y. Mochizuki
Keyword(s):  
Culture Medium ◽  
Primary Cultures ◽  
Minor Component ◽  
Rat Hepatocytes ◽  
Primary Hepatocytes ◽  
Adult Rat ◽  
Adult Rat Hepatocytes ◽  
Epidermal Growth ◽  
A Minor ◽  
Junction Proteins

In the adult rat hepatocyte, the gap junction proteins consist of a major component, connexin32 (Cx32) and a minor component, connexin26 (Cx26). Although we recently reported our success in inducing and maintaining Cx32 in adult rat hepatocytes cultured in serum-free L-15 medium supplemented with epidermal growth factor and 2% dimethyl sulfoxide, it was very difficult to induce Cx26 in the primary hepatocytes. In the present study, we found that the addition of 10(−7) M glucagon into the culture medium could dramatically induce Cx26 mRNA and protein. Although the expression of Cx32 mRNA was also influenced by glucagon, the increase of the expression was small. Immunocytochemically, Cx26-positive spots were observed between most adjacent cells and were co-localized with the Cx32-positive spots. We also examined whether 0.5 mM dibutyl cyclic AMP could induce expression of Cx26 in the cells. The effect of dexamethasone on the expression of Cx26 mRNA compared to that of Cx32 mRNA was examined. For the induction and maintenance of Cx26 mRNA, more than 10(−7) M dexamethasone was necessary in this culture. These results suggest that expression of Cx26 in hepatocytes may be regulated by the concentrations of glucagon and glucocorticoid hormones.

Functional Characterization of GABAA Receptors in Neonatal Hypothalamic Brain Slice

2002 ◽  
Vol 88 (4) ◽  
pp. 1655-1663 ◽  
Author(s):  
Ren-Qi Huang ◽  
Glenn H. Dillon
Keyword(s):  
Functional Characterization ◽  
Minor Component ◽  
Dehydroepiandrosterone Sulfate ◽  
Receptor Subtypes ◽  
Hypothalamic Neurons ◽  
Inhibitory Neurotransmitter ◽  
Old Rats ◽  
A Minor ◽  
Whole Cell Recordings

The hypothalamus influences a number of autonomic functions. The activity of hypothalamic neurons is modulated in part by release of the inhibitory neurotransmitter GABA onto these neurons. GABAA receptors are formed from a number of distinct subunits, designated α, β, γ, δ, ε, and θ, many of which have multiple isoforms. Little data exist, however, on the functional characteristics of the GABAA receptors present on hypothalamic neurons. To gain insight into which GABAA receptor subunits are functionally expressed in the hypothalamus, we used an array of pharmacologic assessments. Whole cell recordings were made from thin hypothalamic slices obtained from 1- to 14-day-old rats. GABAA receptor-mediated currents were detected in all neurons tested and had an average EC50 of 20 ± 1.6 μM. Hypothalamic GABAA receptors were modulated by diazepam (EC50 = 0.060 μM), zolpidem (EC50 = 0.19 μM), loreclezole (EC50 = 4.4 μM), methyl-6,7-dimethoxy-4-ethyl-β-carboline (EC50= 7.7 μM), and 5α-pregnan-3α-hydroxy-20-one (3α-OH-DHP). Conversely, these receptors were inhibited by Zn2+ (IC50 = 70.5 μM), dehydroepiandrosterone sulfate (IC50 = 16.7 μM), and picrotoxin (IC50 = 2.6 μM). The α4/6-selective antagonist furosemide (10–1,000 μM) was ineffective in all hypothalamic neurons tested. The results of our pharmacological analysis suggest that hypothalamic neurons express functional GABAA receptor subtypes that incorporate α1 and/or α2 subunits, β2 and/or β3 subunits, and the γ2 subunit. Our results suggest receptors expressing α3–α6, β1, γ1, and δ, if present, represent a minor component of functional hypothalamic GABAA receptors.

scholarly journals α-Crystallin. The isolation and characterization of distinct macromolecular fractions

1971 ◽  
Vol 124 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Abraham Spector ◽  
Lu-Ku Li ◽  
Robert C. Augusteyn ◽  
Arthur Schneider ◽  
Thomas Freund
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Chemical Difference ◽  
Molecular Weights ◽  
Isolation And Characterization ◽  
Different Populations ◽  
Molecular Weight Fractions

α-Crystallin was isolated from calf lens periphery by chromatography on DEAE-cellulose and gel filtration. Three distinct populations of macromolecules have been isolated with molecular weights in the ranges approx. 6×105−9×105, 0.9×106−4×106and greater than 10×106. The concentration of macromolecules at the molecular-weight limits of a population are very low. The members of the different populations do not appear to be in equilibrium with each other. Further, in those molecular-weight fractions investigated, no equilibrium between members of the same population was observed. The population of lowest molecular weight comprises 65–75% of the total material. The amino acid and subunit composition of the different-sized fractions appear very similar, if not identical. The only chemical difference observed between the fractions is the presence of significant amounts of sugar in the higher-molecular-weight fractions. Subunit molecular weights of approx. 19.5×103and 22.5×103were observed for all α-crystallin fractions.

scholarly journals Isolation and Characterization of 2,3-Dichloro-1-Propanol-Degrading Rhizobia

2000 ◽  
Vol 66 (7) ◽  
pp. 2882-2887 ◽  
Author(s):  
Agus J. Effendi ◽  
Steven D. Greenaway ◽  
Brian N. Dancer
Keyword(s):  
Molecular Weight ◽  
High Ph ◽  
Molecular Weights ◽  
Isolation And Characterization ◽  
Complete Mineralization ◽  
Native Molecular Weight

ABSTRACT 2,3-Dichloro-1-propanol is more chemically stable than its isomer, 1,3-dichloro-2-propanol, and is therefore more difficult to degrade. The isolation of bacteria capable of complete mineralization of 2,3-dichloro-1-propanol was successful only from enrichments at high pH. The bacteria thus isolated were found to be members of the α division of the Proteobacteria in the Rhizobiumsubdivision, most likely Agrobacterium sp. They could utilize both dihaloalcohol substrates and 2-chloropropionic acid. The growth of these strains in the presence of 2,3-dichloro-1-propanol was strongly affected by the pH and buffer strength of the medium. Under certain conditions, a ladder of four active dehalogenase bands could be visualized from this strain in activity gels. The enzyme involved in the complete mineralization of 2,3-dichloro-1-propanol was shown to have a native molecular weight of 114,000 and consisted of four subunits of similar molecular weights.

In vitro culture and non-invasive metabolic profiling of single bovine embryos

2019 ◽  
Vol 31 (2) ◽  
pp. 306
Author(s):  
Monika Nõmm ◽  
Rando Porosk ◽  
Pille Pärn ◽  
Kalle Kilk ◽  
Ursel Soomets ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Metabolic Profiling ◽  
Culture Medium ◽  
Culture Media ◽  
Blastocyst Stage ◽  
Growth Media ◽  
Low Molecular Weight ◽  
Bovine Embryos ◽  
Non Invasive

Selecting high-quality embryos for transfer has been a difficult task when producing bovine embryos invitro. The most used non-invasive method is based on visual observation. Molecular characterisation of embryo growth media has been proposed as a complementary method. In this study we demonstrate a culture medium sampling method for identifying potential embryonic viability markers to predict normal or abnormal embryonic development. During single embryo culture, 20µL culture media was removed at Days 2, 5 and 8 after fertilisation from the same droplet (60µL). In all, 58 samples were analysed using liquid chromatography–mass spectrometry. We demonstrate that it is possible to remove samples from the same culture medium droplets and not significantly affect blastocyst rate (25.2%). Changes in any single low molecular weight compound were not predictive enough. Combining multiple low molecular weight signals made it possible to predict Day 2 and 5 embryo development to the blastocyst stage with an accuracy of 64%. Elevated concentrations of lysophosphatidylethanolamines (m/z=453, 566, 588) in the culture media of Day 8 well-developing embryos were observed. Choline (104m/z) and citrate (215m/z) concentrations were increased in embryos in which development was retarded. Metabolic profiling provides possibilities to identify well-developing embryos before transfer, thus improving pregnancy rates and the number of calves born.

Mechanical and Viscoelastic Characterization of Hyperbranched Polyisobutylenes

2002 ◽  
Vol 75 (5) ◽  
pp. 853-864 ◽  
Author(s):  
Judit E. Puskas ◽  
Christophe Paulo ◽  
Volker Altstädt
Keyword(s):  
Molecular Weight ◽  
Butyl Rubber ◽  
Structure Property ◽  
Carbocationic Polymerization ◽  
Molecular Weights ◽  
Structure Property Relationships ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Living Carbocationic Polymerization

Abstract Structure-property relationships were investigated in hyperbranched polyisobutylenes, in comparison with commercial linear butyl rubber. The gel-free, soluble hyperbranched polyisobutylenes, synthesized by living carbocationic polymerization, had molecular weights, Mw≈400,000 to 1,000,000 g/mol, molecular weight distributions, MWD ≈1.2 to 2.6, and branching frequencies, BR ≈ 4 to 60. The mechanical and viscoelastic characterization of these polymers revealed interesting properties, including the characteristics of crosslinked rubbers.

Synthesis and Properties of Uniform Polyisoprene Networks. I. Synthesis and Characterization of α,ω-Dihydroxy-Polyisoprene

1976 ◽  
Vol 49 (2) ◽  
pp. 303-319 ◽  
Author(s):  
M. Morton ◽  
L. J. Fetters ◽  
J. Inomata ◽  
D. C. Rubio ◽  
R. N. Young
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Soluble Fraction ◽  
Synthesis And Characterization ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
The Subject

Abstract The results of this study are the first to show that high-1,4 linear α,ω-dihydroxypolydienes can be synthesized with (a) predictable molecular weights, (b) narrow molecular weight distributions, and (c) high functionalities. Using the functionalized polyisoprenes prepared in this work, a series of networks was prepared with a purified triisocyanate as the chain linking agent. The soluble fraction in these networks ranged from 4.6 to 1.6 per cent. The characteristics and physical properties of these networks will be the subject of a forthcoming publication.

Particulate glycogen of mammalian liver: specificity in binding phosphorylase and glycogen synthase

1992 ◽  
Vol 70 (7) ◽  
pp. 523-527 ◽  
Author(s):  
Alexander Vardanis
Keyword(s):  
Molecular Weight ◽  
High Performance ◽  
Glycogen Phosphorylase ◽  
Hydrophobic Interactions ◽  
Glycogen Synthase ◽  
Early Period ◽  
Glycogen Particle ◽  
Molecular Weights ◽  
Glycogen Deposition ◽  
A Minor

The glycogen particle – glycogen metabolizing enzyme complex was investigated to gain some understanding of its physiological significance. Fractionations of populations of particles from mouse liver were carried out utilising open column and high performance liquid chromatography, and based either on the molecular weight of the particles or the hydrophobic interactions of the glycogen-associated proteins. The activities of glycogen phosphorylase and glycogen synthase were measured in these fractions. Fractionations were of tissue in different stages of glycogen deposition or mobilization. In animals fed ad libitum, glycogen synthase was associated with the whole spectrum of molecular weights, while the glycogen phosphorylase distribution was skewed in favour of the lower molecular weight species. Under conditions of glycogen mobilization, the phosphorylase distribution changed to include all molecular weights. The hydrophobic interaction separations demonstrated that glycogen synthase binds to a specific subpopulation of particles that is a minor proportion of the total. In general, there was a direct relationship of the total amount of phosphorylase and synthase bound during periods of mobilization and deposition, respectively. Two notable exceptions were the large amounts of glucose-6-P dependent synthase present during the early period of glycogen mobilization and the high amounts of active phosphorylase appearing shortly after food withdrawal, in spite of interim glycogen deposition from presumably already ingested food.Key words: glycogen particle, glycogenolysis, glycogenesis, glycogen phosphorylase, glycogen synthase.

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