Properties of conjugation hormones (erogens) from the basidiomycete Tremella mesenteria

1974 ◽  
Vol 52 (3) ◽  
pp. 521-524 ◽  
Author(s):  
Ian D. Reid
Keyword(s):  
Mating Type ◽  
Active Material ◽  
The Other ◽  
Active Components ◽  
Small Peptides ◽  
Isolation And Identification ◽  
Polar Solvents ◽  
Anion Exchange Resins ◽  
Polystyrene Resin ◽  
Exchange Resins

Hormones produced by haploid cells of one mating type of T. mesenterica and inducing conjugation tubes in the other mating type have been studied in preparation for isolation and identification. The active material can be extracted from aqueous solution with n-butanol, but not with less polar solvents, and is adsorbed on cation and anion exchange resins, charcoal, and neutral polystyrene resin. The molecular weight is probably less than 1000. Three active components can be separated by silica gel column chromatography with a gradient of water in ethanol, or by paper chromatography. The conjugation hormones may be non-polar amino acids or small peptides.

Some Observations on Water-Soluble Factors Which Accelerate the Growth in Aseptic Culture of Larvae of Drosophila Melanogaster

1956 ◽  
Vol 33 (1) ◽  
pp. 142-154
Author(s):  
M. BEGG
Keyword(s):  
Drosophila Melanogaster ◽  
Basal Medium ◽  
Water Soluble ◽  
Soluble Form ◽  
Active Components ◽  
Reduced Pressure ◽  
Aseptic Culture ◽  
Heat Stable ◽  
Anion Exchange Resins ◽  
Exchange Resins

1. An effective technique is described for the aseptic culture of larvae of Drosophila melanogaster. 2. Factors which accelerate the growth of Drosophila in aseptic culture on a basal medium containing casein as a source of amino acids can be extracted from both yeast and pancreas in water-soluble form. 3. Part of the activity of such fractions can be removed by adsorption on anion exchange resins, or on charcoal; and eluted with ammonia. 4. The whole activity is dialysable and recoverable from the dialysate by evaporation under reduced pressure. 5. The active components are heat stable. 6. The active fraction is insoluble in N-butanol, ethanol, acetone, pyridine and ether. 7. Some evidence is presented for the presence of at least two components. 8. The possibility that one of the factors may be a peptide is considered. It is thought unlikely that it is an amino acid.

COMPARAISON DE DIFFERENTES METHODES D’EXTRACTION DU P ASSIMILABLE EN RELATION AVEC LES PROPRIETES CHIMIQUES ET PHYSIQUES DES SOLS DU QUEBEC

1985 ◽  
Vol 65 (1) ◽  
pp. 35-46 ◽  
Author(s):  
T. SEN TRAN ◽  
M. GIROUX
Keyword(s):  
Anion Exchange ◽  
Exchange Resin ◽  
The Other ◽  
Available P ◽  
Soil Group ◽  
Anion Exchange Resins ◽  
Extractable P ◽  
Wide Range ◽  
Exchange Resins ◽  
Bray 1

The objective of this study was to compare different available-P extracting methods on 83 Québec soils. The alkaline Olsen’s method and five acid chemical extractants (Bray-1, Bray-2, new Mehlich, North Carolina double acid DA-4 and DA-10) were compared with each other and with two anion-exchange resin methods. The ratio of P-HCl/P-DAF of Mehlich was used to identify the group of soils with predominant P-Ca forms [Formula: see text]. Within this soil group, the Bray-2, DA-4 and DA-10 methods extracted more P and they were less correlated with all the other methods (r = 0.01 to 0.48*). The Bray-1 and Mehlich methods showed good relationships with Olsen, F−- and HCO3−-form resin methods (r = 0.80** to 0.89**) for this soil group, with the exception that Bray-1 solution was more affected by the presence of free carbonates. In the soil group containing more than 0.6% oxalate-Al, the Bray-1, Bray-2 and DA-10 methods extracted more P than the Mehlich, DA-4 or Olsen methods. The F−-form exchange resin extracted more P than that in the HCO3− form. The depressing effect of free iron oxides on the DA-4 method was also observed with the soil group containing more than 0.6% oxalate-Fe. The contents of DA-4-P were less correlated with those of other methods (r = 0.74** to 0.88**) in this soil group. On the other hand, the Olsen, F− and HCO3− resins extracted more of the P-Fe forms from these soils. The DA-4 method was further influenced by the soil organic matter (OM) contents. The relationships between P-Olsen, P-HCO3−-resin with the other chemical methods were also improved by taking into account the contribution of OM contents. Soil texture influenced mostly Bray-2, Bray-1, DA-4 and DA-10 extractable P. The Mehlich, Olsen and F−-resin extractable P was less affected by clay contents while the HCO3−-resin was the most consistant over a wide range of soil textures. Key words: Available-P, anion-exchange resins, new Mehlich extractant, P-forms, soil testing

Removal of Hydrophobic and Hydrophilic Constituents by Anion Exchange Resin

1999 ◽  
Vol 40 (9) ◽  
pp. 207-214 ◽  
Author(s):  
J.-P. Croué ◽  
D. Violleau ◽  
C. Bodaire ◽  
B. Legube
Keyword(s):  
Molecular Weight ◽  
Anion Exchange ◽  
Water Source ◽  
Atomic Ratio ◽  
Size Exclusion ◽  
Salting Out ◽  
Anion Exchange Resins ◽  
Hydrophilic Character ◽  
Exchange Resins

The objective of this work was to compare the affinity of well characterized NOM fractions isolated from two surface waters with strong (gel matrix and macroporous matrix) and weak anion exchange resins (AER) using batch experiment conditions. The structural characterization of the fraction of NOM has shown that the higher the hydrophilic character, the lower the C/O atomic ratio, the lower the SUVA, the lower the aromatic carbon content and the lower the molecular weight. In general (not always), strong AER was more efficient to remove DOC than weak AER. For the same water source (Suwannee River), the higher the molecular weight of the NOM fraction, the lower the affinity with AER. Increasing the ionic strength favored the removal of the hydrophobic NOM fraction (“salting out” effect) while increasing the pH apparently reduced the removal of the hydrophilic NOM fraction. Results were discussed in terms of size exclusion, adsorption, anion exchange and also hydrophobic/hydrophilic repulsion.

scholarly journals Impact of anion exchange adsorbents on regional citrate anticoagulation

2020 ◽  
pp. 039139882094773
Author(s):  
Karin Strobl ◽  
Stephan Harm ◽  
Ute Fichtinger ◽  
Claudia Schildböck ◽  
Jens Hartmann
Keyword(s):  
Anion Exchange ◽  
Regional Citrate Anticoagulation ◽  
Liver Support ◽  
Anion Exchange Resins ◽  
Increased Risk ◽  
Extracorporeal Liver Support ◽  
Target Molecules ◽  
Exchange Resins ◽  
The Impact

Introduction: Heparin and citrate are commonly used anticoagulants in membrane/adsorption based extracorporeal liver support systems. However, anion exchange resins employed for the removal of negatively charged target molecules including bilirubin may also deplete these anticoagulants due to their negative charge. The aim of this study was to evaluate the adsorption of citrate by anion exchange resins and the impact on extracorporeal Ca2+ concentrations. Methods: Liver support treatments were simulated in vitro. Citrate and Ca2+ concentrations were measured pre and post albumin filter as well as pre and post adsorbents. In addition, batch experiments were performed to quantify citrate adsorption. Results: Pre albumin filter target Ca2+ concentrations were reached well with only minor deviations. Citrate was adsorbed by anion exchange resins, resulting in a higher Ca2+ concentration downstream of the adsorbent cartridges during the first hour of treatment. Conclusions: The anion exchange resin depletes citrate, leading to an increased Ca2+ concentration in the extracorporeal circuit, which may cause an increased risk of clotting during the first hour of treatment. An increase of citrate infusion during the first hour of treatment should therefore be considered to compensate for the adsorption of citrate.

The HML mating-type cassette of Saccharomyces cerevisiae is regulated by two separate but functionally equivalent silencers

1989 ◽  
Vol 9 (11) ◽  
pp. 4621-4630
Author(s):  
D J Mahoney ◽  
J R Broach
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Binding Sites ◽  
The Other ◽  
Functional Domains ◽  
Gene Products ◽  
Cis Acting ◽  
Full Expression ◽  
Mating Type Genes ◽  
Chromosome Iii

Mating-type genes resident in the silent cassette HML at the left arm of chromosome III are repressed by the action of four SIR gene products, most likely mediated through two cis-acting sites located on opposite sides of the locus. We showed that deletion of either of these two cis-acting sites from the chromosome did not yield any detectable derepression of HML, while deletion of both sites yielded full expression of the locus. In addition, each of these sites was capable of exerting repression of heterologous genes inserted in their vicinity. Thus, HML expression is regulated by two independent silencers, each fully competent for maintaining repression. This situation was distinct from the organization of the other silent locus, HMR, at which a single silencer served as the predominant repressor of expression. Examination of identifiable domains and binding sites within the HML silencers suggested that silencing activity can be achieved by a variety of combinations of various functional domains.

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