The influence of a residual group in low-molecular-weight allergoids of Artemisia vulgaris pollen on their allergenicity, IgE- and IgG-binding properties

A silver uptake study by Pseudomonas diminuta was carried out by growing the bacteria in a chloride-free medium (CFM) containing silver ions (50 muM) in a batch culture. From the results, it was found that higher amounts of silver were accumulated inside the cell during early exponential phase compared to the amount bound at the cell surface. This suggested a possible mechanism for metal uptake during bacterial growth. In view of this, attempts were made to isolate proteins which might be associated with silver-binding properties from cultures of P.diminuta grown in the presence and absence of silver. The proteins were first extracted from the bacterial cultures by precipitation with ammonium sulfate followed by purification using isoelectric focussing and SDS-PAGE. Results of the experiment showed the presence of low molecular weight and high molecular weight proteins containing silver with pI values ranging from 2.0 to 9.0 for bacteria grown in the presence of silver.

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Heparin-induced Thrombocytopenia: IgG Binding to PF4-Heparin Complexes in the Fluid Phase and Cross-reactivity with Low Molecular Weight Heparin and Heparinoid

Thrombosis and Haemostasis ◽

10.1055/s-0037-1615190 ◽

1998 ◽

Vol 80 (08) ◽

pp. 292-297 ◽

Cited By ~ 80

Author(s):

Peter Newman ◽

Rebecca Swanson ◽

Beng Chong

Keyword(s):

Molecular Weight ◽

Fluid Phase ◽

Cross Reactivity ◽

Low Molecular Weight ◽

Absolute Contraindication ◽

Low Molecular Weight Heparins ◽

Heparin Induced Thrombocytopenia ◽

Igg Binding ◽

Heparin Complexes ◽

Low Levels

SummaryEarly diagnosis of heparin-induced thrombocytopenia (HIT) is essential to reduce morbidity and mortality. We report an enzyme immunoassay which detects the binding of HIT IgG to PF4-heparin in the fluid phase. Our fluid phase assay produces consistently low background and can detect low levels of anti-PF4-heparin. It is suited to testing alternative anticoagulants because, unlike in an ELISA, a clearly defined amount of antigen is available for antibody binding. We were able to detect anti-PF4-heparin IgG in 26/28 (93%) HIT patients. We investigated cross-reactivity of anti-PF4-heparin antibodies with PF4 complexed to alternative heparin-like anticoagulants. Low molecular weight heparins cross-reacted with 23/26 (88%) of the sera from HIT patients while half of the HIT sera weakly cross-reacted with PF4-danaparoid (Orgaran). The thrombocytopenia and thrombosis of most of these patients resolved during danaparoid therapy, indicating that detection of low affinity antibodies to PF4-danaparoid by immunoassay may not be an absolute contraindication for danaparoid administration.

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Poly(vinylbenzo macrocyclic polyethers). Synthesis and cation binding properties of 12-crown-4 derivatives

Canadian Journal of Chemistry ◽

10.1139/v91-105 ◽

1991 ◽

Vol 69 (4) ◽

pp. 702-705 ◽

Cited By ~ 5

Author(s):

G. W. Buchanan ◽

J. K. Denike

Keyword(s):

Molecular Weight ◽

Methylene Chloride ◽

Cation Binding ◽

Cooperative Binding ◽

Low Molecular Weight ◽

Binding Properties ◽

Macrocyclic Polyethers ◽

Free Radical Initiator ◽

Salt Distribution ◽

Distribution Equilibria

The synthesis of 4′-vinylbenzo-12-crown-4 ether is reported. Polymerization to relatively low molecular weight polymers can be accomplished with a free radical initiator. A copolymer with styrene can be prepared and the Li+, Na+, and K+ binding properties of these polymers are compared to those of their monomeric analogs using salt distribution equilibria in water – methylene chloride. For all cations the homopolymer is found to extract the salts from the aqueous phase most effectively. The copolymer is slightly less effective than the homopolymer but more effective than either of the monomers by a factor of approximately 7, indicating that cooperative binding is likely. Na+ is the most efficiently extracted cation, followed by K+ and Li+. Key words: crown ether polymers, complexation properties.

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IgG binding of mugwort pollen allergens and allergoids exposed to simulated gastrointestinal conditions measured by a self-developed ELISAtest

Journal of the Serbian Chemical Society ◽

10.2298/jsc0407533p ◽

2004 ◽

Vol 69 (7) ◽

pp. 533-540 ◽

Cited By ~ 3

Author(s):

Natalija Polovic ◽

Tanja Cirkovic-Velickovic ◽

Marija Gavrovic-Jankulovic ◽

Lidija Burazer ◽

Danica Djergovic-Petrovic ◽

...

Keyword(s):

Prolonged Exposure ◽

Binding Potential ◽

Pollen Extract ◽

Artemisia Vulgaris ◽

Pollen Allergens ◽

Binding Properties ◽

Gastrointestinal Conditions ◽

Igg Binding ◽

Specific Igg ◽

Acidic Conditions

This study considers the influence of exposure to simulated gastrointestinal conditions (saliva, gut, intestine and acidic conditions of the gut) on IgG binding of unmodified allergens and three types of LMW allergoids of Artemisia vulgaris pollen extract obtained by means of potassium cyanate succinic and maleic anhydride. It also concerns the optimization of a self-developed ELISA assay for comparison of the specific IgG binding of mugwort pollen extract and modified mugwort pollen derivatives. The ELISA was conducted with a mugwort pollen extract coupled to the plate, using the sera from 12 mugwort- pollen allergic patients. The exposure to saliva fluid for 2 min did not influence the IgG binding properties of allergens and allergoids. Exposure of mugwort pollen allergens and LMW allergoids to the acidic conditions of the gut did not dramatically change their IgG binding properties. By exposing mugwort pollen extract and LMW derivatives to the SGF conditions for 1 h, the percent of IgG binding epitopes was reduced to a half of its starting value in the extract and to about 30%in all the allergoid samples. After prolonged exposure only the carbamyl derivative showed reduced IgG binding. Changes of the IgG binding potential of all four samples after exposure in SIF followed a similar pattern.

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The Plant Toxin Victorin Binds to a Discrete Number of Proteins in All Organisms Tested

Functional Plant Biology ◽

10.1071/pp9940243 ◽

1994 ◽

Vol 21 (2) ◽

pp. 243 ◽

Cited By ~ 2

Author(s):

DC Loschke ◽

LD Tomaska ◽

H Chen ◽

DW Gabriel ◽

BG Rolfe

Keyword(s):

Molecular Weight ◽

Plant Species ◽

Binding Proteins ◽

Low Molecular Weight ◽

In Vitro Experiments ◽

Plant Toxin ◽

Binding Properties ◽

Saprophytic Fungus ◽

Biological Probe

We have used the plant toxin victorin C, which is synthesised by the saprophytic fungus Cochliobolus victoria, as a biological probe. Victorin C, labelled with either 125I or 35S, bound to eight distinct proteins (victorin-binding proteins) in oat plants that were either resistant or sensitive to the toxin. Using a series of in vitro experiments, we observed a difference in the victorin-binding properties between resistant and susceptible plants. Furthermore, we found that other plant species contain a set of proteins of similar sizes which specifically bind victorin. Unexpectedly, we also found a low molecular weight victorin-binding protein present in all tested eukaryotic and prokaryotic cells.

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Determination of binding properties of low molecular weight substances to proteins using ultracentrifugation

Analytical Biochemistry ◽

10.1016/0003-2697(70)90137-5 ◽

1970 ◽

Vol 34 (2) ◽

pp. 517-528 ◽

Cited By ~ 8

Author(s):

Helga Hirsch-Kolb ◽

Helmut J. Kolb ◽

David M. Greenberg

Keyword(s):

Molecular Weight ◽

Low Molecular Weight ◽

Binding Properties

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A high-performance oil-free backing pump for electron microscopes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100107691 ◽

1978 ◽

Vol 36 (1) ◽

pp. 110-111

Author(s):

G.K.W. Balkau ◽

E. Bez ◽

J.L. Farrant

Keyword(s):

Molecular Weight ◽

Electron Microscope ◽

Hot Spots ◽

High Performance ◽

Carbonaceous Material ◽

Contamination Rate ◽

Low Molecular Weight ◽

Principal Source ◽

Rotary Pumps ◽

Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

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