scholarly journals Low-Temperature Isolation of Disease-Suppressive Bacteria and Characterization of a Distinctive Group of Pseudomonads

2003 ◽  
Vol 69 (11) ◽  
pp. 6464-6474 ◽  
Author(s):  
P. Maria Johansson ◽  
Sandra A. I. Wright
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Arable Land ◽  
Fusarium Culmorum ◽  
Wheat Seedling ◽  
Morphological Group ◽  
Drechslera Teres ◽  
Barley Net Blotch ◽  
The Impact

ABSTRACT The influence of environmental factors during isolation on the composition of potential biocontrol isolates is largely unknown. Bacterial isolates that efficiently suppressed wheat seedling blight caused by Fusarium culmorum were found by isolating psychrotrophic, root-associated bacteria and by screening them in a bioassay that mimicked field conditions. The impact of individual isolation factors on the disease-suppressive index (DSI) of almost 600 isolates was analyzed. The bacteria originated from 135 samples from 62 sites in Sweden and Switzerland. The isolation factors that increased the probability of finding isolates with high DSIs were sampling from arable land, Swiss origin of samples, and origination of isolates from plants belonging to the family Brassicaceae. The colony morphology of the isolates was characterized and compared to DSIs, which led to identification of a uniform morphological group containing 57 highly disease-suppressive isolates. Isolates in this group were identified as Pseudomonas sp.; they were fluorescent on King's medium B and had characteristic crystalline structures in their colonies. These isolates were morphologically similar to seven strains that had previously been selected for suppression of barley net blotch caused by Drechslera teres. Members of this morphological group grow at 1.5°C and produce an antifungal polyketide (2,3-deepoxy-2,3-didehydrorhizoxin [DDR]). They have similar two-dimensional polyacrylamide gel electrophoresis protein profiles, phenotypic characteristics, and in vitro inhibition spectra of pathogens. In summary, in this paper we describe some isolation factors that are important for obtaining disease-suppressive bacteria in our system, and we describe a novel group of biocontrol pseudomonads.

scholarly journals Influence of Pasteurization and Storage on Dynamic In Vitro Gastric Digestion of Milk Proteins: Quantitative Insights Based on Peptidomics

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 998 ◽  
Author(s):  
Xing Li ◽  
Yuxiang Gu ◽  
Shudong He ◽  
Olayemi Eyituoyo Dudu ◽  
Qiming Li ◽  
...  
Keyword(s):  
Cold Storage ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Milk Proteins ◽  
Hydrolysis Rate ◽  
Gastric Digestion ◽  
Pasteurized Milk ◽  
The Impact ◽  
And Storage

It is important to evaluate the nutritional quality of milk during the shelf-life, especially during home storage, from a consumer viewpoint. In this study, we investigated the impact of pasteurization (85 °C/15 s) and subsequent storage (at 4 °C for 7 days) on the coagulation behavior of milk and protein digestibility in a dynamic in vitro gastric digestion test. A high level of hydration in curd formed in pasteurized milk upon 7-day cold storage compared to raw and pasteurized milk, indicating fast pepsin diffusion in the interior of curds, increasing the hydrolysis rate. The digesta collected at various time points throughout the gastric digestion were studied using o-phthaldialdehyde (OPA), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), liquid chromatography tandem mass spectrometry (LC-MS/MS), and amino acid analysis. These results showed that milk proteins were hydrolyzed quickly upon a long period of cold storage. Additionally, qualitative and quantitative results obtained using LC-MS/MS exhibited significant differences between samples, especially in pasteurized milk upon cold storage. Processing and storage played a decisive role in bioactive peptide generation. Such knowledge could provide insights into and directions for the storage of pasteurized milk for further clinical studies on protein bioavailability and the generation of bioactive peptides for desired health outcomes.

scholarly journals MR imaging of model drug distribution in simulated vitreous

2015 ◽  
Vol 1 (1) ◽  
pp. 236-239 ◽  
Author(s):  
Sandra Stein ◽  
Christian Simroth-Loch ◽  
Sönke Langner ◽  
Stefan Hadlich ◽  
Oliver Stachs ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ex Vivo ◽  
Drug Distribution ◽  
Injection Technique ◽  
Innovative Therapy ◽  
Age Related ◽  
The Impact

AbstractThe in vitro and in vivo characterization of intravitreal injections plays an important role in developing innovative therapy approaches. Using the established vitreous model (VM) and eye movement system (EyeMoS) the distribution of contrast agents with different molecular weight was studied in vitro. The impact of the simulated age-related vitreal liquefaction (VL) on drug distribution in VM was examined either with injection through the gel phase or through the liquid phase. For comparison the distribution was studied ex vivo in the porcine vitreous. The studies were performed in a magnetic resonance (MR) scanner. As expected, with increasing molecular weight the diffusion velocity and the visual distribution of the injected substances decreased. Similar drug distribution was observed in VM and in porcine eye. VL causes enhanced convective flow and faster distribution in VM. Confirming the importance of the injection technique in progress of VL, injection through gelatinous phase caused faster distribution into peripheral regions of the VM than following injection through liquefied phase. VM and MR scanner in combination present a new approach for the in vitro characterization of drug release and distribution of intravitreal dosage forms.

Cellular and molecular characterization of the impact of laboratory setup on bovine in vitro embryo production

2012 ◽  
Vol 77 (9) ◽  
pp. 1767-1778.e1 ◽  
Author(s):  
Dany Plourde ◽  
Christian Vigneault ◽  
Isabelle Laflamme ◽  
Patrick Blondin ◽  
Claude Robert
Keyword(s):  
Molecular Characterization ◽  
Embryo Production ◽  
Laboratory Setup ◽  
In Vitro Embryo Production ◽  
The Impact

scholarly journals Purification and characterization of a mannose-containing disaccharide obtained from human pregnancy urine. A new immunoregulatory saccharide.

1984 ◽  
Vol 160 (6) ◽  
pp. 1672-1685 ◽  
Author(s):  
A V Muchmore ◽  
J M Decker ◽  
R M Blaese ◽  
B Nilsson
Keyword(s):  
Lymphocyte Culture ◽  
Membrane Receptors ◽  
Cell Wall Polysaccharide ◽  
Human Pregnancy ◽  
Isolation And Characterization ◽  
Pregnancy Urine ◽  
The Impact

Endogenous mammalian lectin-like sugar-binding molecules have been previously described that have immunoregulatory properties. Further, the addition of defined simple saccharides to lymphocyte cultures has been shown to inhibit a variety of in vitro lymphocyte functions, presumably because these sugars are able to compete with the binding of endogenous lectins to critical membrane receptors. In this report, we describe the isolation and characterization of a D-mannose-containing disaccharide in human pregnancy urine that inhibits the proliferative response of human T lymphocytes. The inhibitory disaccharide was purified to homogeneity by sequential steps including affinity chromatography on immobilized concanavalin A and molecular sizing on Sephadex G-75 and then Fractogel 40S columns, with final purification on high-performance thin-layer chromatography. By mass spectrometry of the purified material as its permethylated derivative, the deduced structure of this compound was alpha-D-Manp 1-6-D-Man. To confirm that this disaccharide was in fact immunosuppressive, an identical disaccharide was prepared by sequential digestion of yeast cell wall polysaccharide. The urinary and yeast disaccharides had identical immunosuppressive properties. It has been previously reported that D-mannose is inhibitory for antigen-specific proliferative assays in the range of 10-50 mM. The purified alpha-D-Manp 1-6-D-Man disaccharide was inhibitory at 100-fold-lower concentrations. Further, while D-mannose inhibits T cell proliferation when added at anytime up to 24 h before harvest of a 6-d lymphocyte culture, alpha-D-Manp 1-6-D-Man disaccharide was inhibitory only if added at the initiation of culture and had no inhibitory effect if added just 24 h later. These data support the concept that simple sugar compounds can exhibit marked immunoregulatory activity in vitro. The impact of these molecules on the regulation of immune responses in vivo is unknown, as is their precise mechanism of action, but structural and chemical identification should now permit a detailed analysis of these issues.

scholarly journals Characterization of compounds shed from the surface of human leukemic myeloblasts in vitro

Blood ◽  
1982 ◽  
Vol 60 (2) ◽  
pp. 412-419 ◽  
Author(s):  
MA Baker ◽  
DA Roncari ◽  
RN Taub ◽  
T Mohanakumar ◽  
JA Falk ◽  
...  
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Active Material ◽  
Myelogenous Leukemia ◽  
Leukemic Cells ◽  
Gel Chromatography ◽  
Acute Myelogenous ◽  
Immune Precipitation ◽  
M1 Type

Abstract Human leukemic myeloblasts shed glycoproteins from the cell surface during short-term in vitro culture. Shed surface glycoproteins yield a characteristic profile when studied by gel chromatography, isoelectric focusing, immune precipitation, and polyacrylamide gel electrophoresis. Isolation of immunologically active material yields a compound to approximately 75,000--80,000 daltons, with an isoelectric point of 7.6 to 7.9. Various morphological subtypes of acute myelogenous leukemia shed these compounds, but they are most easily obtained from the more differentiated M2 and M4 types as compared to the undifferentiated M1 type. The shed compounds appear to be quantitatively and qualitatively different from compounds shed by other leukemic cells or nonleukemic cells.

scholarly journals Isolation and characterization of lung connective-tissue glycoproteins

1982 ◽  
Vol 203 (3) ◽  
pp. 593-601 ◽  
Author(s):  
C Lafuma ◽  
M Moczar ◽  
L Robert
Keyword(s):  
Proteinase Inhibitors ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Lung Parenchyma ◽  
Isolation And Characterization ◽  
Isoelectric Points ◽  
And Function

1. Glycoproteins of hamster, rat and baboon lung parenchyma were investigated by using [14C]glucosamine incorporation in vitro followed by sequential extraction of the macromolecular components and characterization of the glycoproteins in the extracts. 2. Slices of lung parenchyma maintained in vitro incorporated [U-14C]glucosamine linearly with time into non-diffusible macromolecules for up to 5h. All the macromolecule-associated 14C label was present as [14C]glucosamine. 3. These 14C-labelled macromolecules were extracted from previously delipidated and salt-extracted lung by 5M-guanidinium chloride in the presence of dithiothreitol and proteinase inhibitors before (extract A1) and after (extract A2) hydrolysis of the collagen by collagenase. The [14C]glucosamine-labelled glycoproteins in extracts A1 and A2 contained 55 and 5% respectively of the total [14C]glucosamine incorporated in the lung of all three species studied. 4. The [14C]glucosamine-labelled glycoproteins were analysed by gel-filtration chromatography, sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and isoelectric focusing. The major [14C]glucosamine-labelled glycoproteins of baboon lung parenchyma had apparent mol.wts. of about 400 000, 140 000 and 65 000 with isoelectric points respectively of 4.8, 5.4 and 5.4. The hamster lung glycoproteins with isoelectric points of 4.1 and 5.8 were devoid of hydroxyproline and contained galactose, mannose and N-acetylglucosamine. These experiments indicate that several distinct glycoproteins are synthesized in situ by the cells of pulmonary parenchyma and may well play a role in its structure and function.

scholarly journals Purification and characterization of the 27,000 Da calcium-binding protein of bovine brain

1987 ◽  
Vol 244 (2) ◽  
pp. 401-408 ◽  
Author(s):  
M Tokuda ◽  
N C Khanna ◽  
D M Waisman
Keyword(s):  
Calcium Binding ◽  
Binding Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sedimentation Coefficient ◽  
Bovine Brain ◽  
Stokes Radius ◽  
Acidic Nature ◽  
Bovine Pancreas

A Ca2+-binding protein named CAB-27 was purified from bovine brain 100,000 g supernatant. The protein has a molecular mass of 27,000 Da as determined by SDS/polyacrylamide-gel electrophoresis and 35,500 Da by sedimentation-coefficient and Stokes-radius analysis. The protein contains about 26% Glx and Asx and 13% basic residues. The acidic nature of the molecule is confirmed by its pI of 4.80. In the presence of 3 mM-MgCl2 and 150 mM-KCl, CAB-27 binds 2.0 mol of Ca2+/mol of protein, with an apparent Kd of 0.2 microM. Ca2+-binding is unaffected by prior incubation of the protein at 80 degrees C for 2 min. Brain contains about 130 mg of CAB-27/kg. Immunoblotting identified CAB-27 in several bovine tissues; it appears to be particularly rich in brain and kidney. In addition, CAB-27 is identified as an inhibitor of bovine pancreas phospholipase A2 in vitro. The inhibitory activity of CAB-27 was 20-fold less potent than lipocortin. On the basis of the Ca2+-binding properties, intracellular concentration and tissue distribution of this protein, we suggest that CAB-27 may be an important intracellular Ca2+ receptor.

scholarly journals Antifungal Activity Toward Fusarium culmorum in Soluble Wheat Extracts

2000 ◽  
Vol 90 (6) ◽  
pp. 666-671 ◽  
Author(s):  
F. M. Doohan ◽  
A. Mentewab ◽  
P. Nicholson
Keyword(s):  
Antifungal Activity ◽  
Ammonium Sulfate ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Fusarium Culmorum ◽  
Gel Filtration ◽  
Head Blight ◽  
Inhibitory Compounds ◽  
Molecular Masses

This study investigated antifungal activity in soluble extracts from seed of a range of wheat cultivars differing in susceptibility to Fusarium head blight. Antifungal activity was assessed in terms of β-D-glucuronidase (GUS) activity of a Fusarium culmorum GUS transformant using a sensitive laboratory assay. Significant antifungal activity was detected in seed extracts from WEK0609, CM 820036, and Arina. Initial characterization of the Arina seed extract indicated that it contained antifungal proteinaceous compounds. The Arina extract yielded two (60 and 80%) ammonium sulfate fractions containing inhibitory compounds. Gel filtration chromatography and subsequent sodium dodecyl sulfate-polyacrylamide gel electrophoresis of antifungal fractions showed that the antifungal activities detected in the Arina 60 and 80% ammonium sulfate fractions were associated with putative proteinaceous compounds with apparent molecular masses of approximately 60 and 28 kDa, respectively.

scholarly journals Hazelnut (Corylus avellana) vicilin Cor a 11: molecular characterization of a glycoprotein and its allergenic activity

2004 ◽  
Vol 383 (2) ◽  
pp. 327-334 ◽  
Author(s):  
Iris LAUER ◽  
Kay FOETISCH ◽  
Daniel KOLARICH ◽  
Barbara K. BALLMER-WEBER ◽  
Amedeo CONTI ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Corylus Avellana ◽  
Cd Spectroscopy ◽  
Mediator Release ◽  
Food Allergies ◽  
Ige Reactivity ◽  
Allergenic Activity ◽  
The Impact

In Europe, hazelnuts (Corylus avellana) are a frequent cause of food allergies. Several important hazelnut allergens have been previously identified and characterized. Specific N-glycans are known to induce strong IgE responses of uncertain clinical relevance, but so far the allergenic potential of glycoproteins from hazelnut has not been investigated. The aim of the study was the molecular characterization of the glycosylated vicilin Cor a 11 from hazelnut and the analysis of its allergenic activity. Although MALDI–TOF (matrix-assisted laser-desorption ionization–time-of-flight) MS showed that one of two potential glycosylation sites of Cor a 11 was glycosylated, CD spectroscopy indicated that recombinant and natural Cor a 11 share similar secondary structures. Thus to analyse the impact of the glycan residues of Cor a 11 on IgE binding, the allergenic activity of natural glycosylated Cor a 11 and recombinant Cor a 11 was compared. In addition, the IgE sensitization pattern to recombinant Cor a 11, Cor a 1, Cor a 2 and Cor a 8 of 65 hazelnut allergic patients was determined in vitro. The prevalence of IgE reactivity to hazelnut vicilin Cor a 11 was below 50%. Basophil histamine-release assays were used to determine the allergenic activity of both natural and recombinant Cor a 11 in comparison with Cor a 1, a birch (Betula verrucosa) pollen-related major hazelnut allergen. Both forms of Cor a 11 induced mediator release from basophils to a similar extent, indicating that the hazelnut allergic patients had cross-linking IgE antibodies binding to the protein backbone and not to carbohydrate structures. In comparison to Cor a 1, a 10000-fold higher concentration of Cor a 11 was required to induce similar basophil mediator release. In conclusion, the hazelnut vicilin Cor a 11 is a minor allergen both in regard to prevalence and allergenic potency, whereas its glycan does not contribute to its allergenic activity.

Sign in / Sign up

Export Citation Format

Share Document