scholarly journals Seed-competent tau monomer initiates pathology in PS19 tauopathy mice

2022 ◽  
Author(s):  
Hilda Mirbaha ◽  
Dailu Chen ◽  
Vishruth Mullapudi ◽  
Sandi Jo Estill Terpack ◽  
Charles L. White ◽  
...  
Keyword(s):  
Mouse Model ◽  
Biologically Active ◽  
Size Exclusion ◽  
Protein Assemblies ◽  
Post Translational Modifications ◽  
Conformational Ensembles ◽  
Insoluble Material ◽  
Repeat Domain ◽  
Exclusion Chromatography ◽  
Tau Aggregation

Tau aggregation into ordered assemblies causes myriad neurodegenerative tauopathies. We previously reported that tau monomer exists in either inert (Mi) or seed-competent (Ms) conformational ensembles, and that Ms encodes strains, which are biologically active, self-propagating assemblies. We have previously isolated Ms from tauopathy brains, but it is unknown if disease begins with Ms formation followed by fibril assembly, or if Ms derives from fibrils and is an epiphenomenon. Consequently, we studied a tauopathy mouse model (PS19) that expresses full-length human (1N4R) tau containing a disease-associated mutation (P301S). Using tau repeat domain biosensor cells, we detected insoluble tau seeding activity at 2 months. We found insoluble tau protein assemblies by immunoblot at 3 months. We next immunopurified monomer from mice aged 1-6 weeks using size exclusion chromatography. We detected soluble seeding activity at 4 weeks, before insoluble material or larger assemblies, with assemblies ranging from n=1-3 tau units. By 5 and 6 weeks, large soluble assemblies had formed. This indicated the first detectable pathological forms of tau were Ms. We next tested for post-translational modifications of tau monomer from 1-6 weeks. We detected no phosphorylation unique to Ms in PS19 or Alzheimer disease brain. We conclude that tauopathy begins with formation of Ms monomer, whose activity is phosphorylation-independent. Ms self-assembles to form oligomers before it forms insoluble fibrils. The conversion of tau monomer from Mi to Ms thus constitutes the first detectable step in the initiation of tauopathy in this mouse model, with obvious implications for origins of disease in humans.

Characterisation of Persistent Anti-Xa Activity Following Administration of the Low Molecular Weight Heparin Enoxaparin Sodium (Clexane)

1994 ◽  
Vol 72 (02) ◽  
pp. 275-280 ◽  
Author(s):  
David Brieger ◽  
Joan Dawes
Keyword(s):  
Molecular Weight ◽  
Enoxaparin Sodium ◽  
Antithrombin Iii ◽  
Anticoagulant Activity ◽  
Active Material ◽  
Biologically Active ◽  
Size Exclusion ◽  
Low Molecular Weight ◽  
Exclusion Chromatography ◽  
Liver And Kidney

SummaryIt is widely reported that persistent anti-Xa activity follows administration of low molecular weight heparins. To identify the effectors of this activity we have injected 125I-labelled Enoxaparin sodium into rabbits and subsequently analysed the circulating radiolabelled material and anti-Xa activity by affinity and size exclusion chromatography. Antithrombin III-binding material derived from the injected drug was responsible for all the anti-Xa amidolytic activity. At early times after injection additional anticoagulant activity which was largely attributable to tissue factor pathway inhibitor was measured by the Heptest clotting assay after removal of glycosaminoglycans from plasma samples. Small radiolabelled fragments, including penta/hexasaccharide with affinity for antithrombin III, were detectable in the circulation 1 week later, and sulphated oligosaccharides persisted for 3-4 weeks. Significant quantities of radiolabel remained in the liver and kidney several weeks post-injection; these organs may sequester some of the injected drug and give rise to circulating biologically active material by degradation and secretion of catabolic products into the plasma.

scholarly journals Characterization of a monoclonal antibody directed against the biologically active site of human interleukin 1.

1986 ◽  
Vol 163 (2) ◽  
pp. 463-468 ◽  
Author(s):  
A Köck ◽  
M Danner ◽  
B M Stadler ◽  
T A Luger
Keyword(s):  
Monoclonal Antibody ◽  
Active Site ◽  
Biological Effects ◽  
Interleukin 1 ◽  
Biologically Active ◽  
Size Exclusion ◽  
Fibroblast Proliferation ◽  
Initial Activity ◽  
Exclusion Chromatography

Human IL-1 was successfully used to produce an anti-IL-1 mAb. Anti-IL-1 (IgG2a) blocked IL-1-mediated thymocyte and fibroblast proliferation, but did not interfere with the biological effects of other lymphokines, such as IL-2 or IL-3. The antibody immunoprecipitated biosynthetically radiolabeled 33, 17, and 4 kD IL-1. An immunoadsorbent column yielded 20% of initial activity, and upon HPLC size-exclusion chromatography, affinity-purified IL-1 had a molecular mass of approximately 4 kD. These results provide first evidence of a monoclonal anti-IL-1 that reacts with different species of IL-1 and apparently binds to an epitope close to the active site of IL-1. Thus, anti-IL-1 IgG may be very helpful for further investigations of the molecular as well as biological characteristics of IL-1 and related mediators.

scholarly journals Processed Fruiting Bodies of Lentinus edodes as a Source of Biologically Active Polysaccharides

2020 ◽  
Vol 10 (2) ◽  
pp. 470 ◽  
Author(s):  
Marta Ziaja-Sołtys ◽  
Wojciech Radzki ◽  
Jakub Nowak ◽  
Jolanta Topolska ◽  
Ewa Jabłońska-Ryś ◽  
...  
Keyword(s):  
Biological Activities ◽  
Water Soluble ◽  
Biologically Active ◽  
Size Exclusion ◽  
Lentinus Edodes ◽  
Fruiting Bodies ◽  
Antioxidant Power ◽  
Exclusion Chromatography ◽  
Processing Techniques ◽  
The Impact

Water soluble polysaccharides (WSP) were isolated from Lentinus edodes fruiting bodies. The mushrooms were previously subjected to various processing techniques which included blanching, boiling, and fermenting with lactic acid bacteria. Therefore, the impact of processing on the content and biological activities of WSP was established. Non-processed fruiting bodies contained 10.70 ± 0.09 mg/g fw. Boiling caused ~12% decrease in the amount of WSP, while blanched and fermented mushrooms showed ~6% decline. Fourier transform infrared spectroscopy analysis (FTIR) confirmed the presence of β-glycosidic links, whereas due to size exclusion chromatography 216 kDa and 11 kDa molecules were detected. WSP exhibited antioxidant potential in FRAP (ferric ion reducing antioxidant power) and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assays. Cytotoxic properties were determined on MCF-7 and T47D human breast cell lines using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) test. Both biological activities decreased as the result of boiling and fermenting.

scholarly journals Partial Chemical Characterization of Immunomodulatory Polysaccharides from Plantago palmata Hook. f. s. Leaves

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Gabriel Biringanine ◽  
Moustapha Ouedraogo ◽  
Bernard Vray ◽  
Anne Berit Samuelsen ◽  
Pierre Duez
Keyword(s):  
Chemical Structure ◽  
Chemical Characterization ◽  
Biologically Active ◽  
Size Exclusion ◽  
Plantago Major ◽  
Activated Macrophages ◽  
Exclusion Chromatography ◽  
Very High ◽  
Partial Chemical

A previous work on Plantago palmata polysaccharides (PS) attributed immunomodulatory properties of leaves to a polysaccharide fraction (PS50) that stimulated NO and TNF-α production by interferon gamma- (IFN-γ-) activated macrophages. The present work aims to elucidate the chemical structure of these immunomodulatory polysaccharides. Size exclusion chromatography showed that the active polymers present an active fraction with a very high molecular weight (about 1200 kDa). These polysaccharides are pectic in nature, with a predominantly unbranched galacturonan domain and with a domain bearing side chains that consist of highly branched arabinan, galactan, and/or arabinogalactan. Comparatively to the well-known Plantago major biologically active PS, Plantago palmata PS50 contained less arabinogalactan-proteins (AGPs) and had a different composition in glucose, galactose, and galacturonic acid. DNA contamination of the polysaccharide was estimated at about 0.04%, a concentration much lower than those reported immunomodulatory in hyaluronic acid preparations (3 to 15%). Therefore, the eventuality of a contaminating DNA-mediated biological activity could be ruled out.

scholarly journals Microanalysis Characterization of Bioactive Protein-Bound Polysaccharides Produced by Amanita Ponderosa Cultures

2014 ◽  
Vol 21 (1) ◽  
pp. 84-90 ◽  
Author(s):  
Cátia Salvador ◽  
M. Rosário Martins ◽  
A. Teresa Caldeira
Keyword(s):  
Accelerated Aging ◽  
Artemia Salina ◽  
Quercus Suber ◽  
Attenuated Total Reflection ◽  
Biologically Active ◽  
Edible Mushrooms ◽  
Size Exclusion ◽  
Molecular Weights ◽  
Exclusion Chromatography ◽  
Biotechnological Processes

AbstractDifferent compounds of edible mushrooms are responsible for their bioactivity. The ability to synthesize polysaccharides, namely protein–polysaccharide (PPS) complexes, is related to the antioxidant capacity of these compounds and present great interest in preventing a number of diseases, including cancer, cardiovascular and auto-immune diseases, and accelerated aging. Amanita ponderosa are wild edible mushrooms that grow in Mediterranean “montado” areas [Portuguese name given to cork oak (Quercus suber) and holm oak (Quercus ilex) forests]. The aim of this study was to evaluate the production of PPS complexes obtained from A. ponderosa cultures using a new microanalytical approach to quickly and easily monitor the production process. Microanalysis using Fourier-transform infrared using attenuated total reflection and Raman spectroscopy of PPS samples showed spectra compatible with identification of this type of compound in culture extracts. PPS separated by size-exclusion chromatography showed seven main complexes. Molecular weights of the main PPS complexes isolated from cultures ranged between 1.5 and 20 kDa and did not present toxicity against Artemia salina, demonstrating the potential of A. ponderosa as a source of biologically active compounds with nutraceutical value. Application of this microanalytical approach to monitoring the production of PPS compounds can be successfully applied in biotechnological processes.

scholarly journals A Use of Tritium-Labeled Peat Fulvic Acids and Polyphenolic Derivatives for Designing Pharmacokinetic Experiments on Mice

Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1787
Author(s):  
Gennady A. Badun ◽  
Maria G. Chernysheva ◽  
Yury V. Zhernov ◽  
Alina S. Poroshina ◽  
Valery V. Smirnov ◽  
...  
Keyword(s):  
Fulvic Acid ◽  
Fulvic Acids ◽  
Biologically Active ◽  
Size Exclusion ◽  
Pharmacokinetic Studies ◽  
Ion Cyclotron Resonance ◽  
Natural Systems ◽  
Exclusion Chromatography ◽  
Distribution Studies ◽  
Label Distribution

Natural products (e.g., polyphenols) have been used as biologically active compounds for centuries. Still, the mechanisms of biological activity of these multicomponent systems are poorly understood due to a lack of appropriate experimental techniques. The method of tritium thermal bombardment allows for non-selective labeling and tracking of all components of complex natural systems. In this study, we applied it to label two well-characterized polyphenolic compounds, peat fulvic acid (FA-Vi18) and oxidized lignin derivative (BP-Cx-1), of predominantly hydrophilic and hydrophobic character, respectively. The identity of the labeled samples was confirmed using size exclusion chromatography. Using ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT ICR MS), key differences in the molecular composition of BP-Cx-1 and FA-Vi18 were revealed. The labeled samples ([3H]-FA-Vi18 (10 mg/kg) and [3H]-BP-Cx-1 (100 mg/kg)) were administered to female BALB/c mice intravenously (i.v.) and orally. The label distribution was assessed in blood, liver, kidneys, brain, spleen, thymus, ovaries, and heart using liquid scintillation counting. Tritium label was found in all organs studied at different concentrations. For the fulvic acid sample, the largest accumulation was observed in the kidney (Cmax 28.5 mg/kg and 5.6 mg/kg, respectively) for both routes. The organs of preferential accumulation of the lignin derivative were the liver (Cmax accounted for 396.7 and 16.13 mg/kg for i.v. and p.o. routes, respectively) and kidney (Cmax accounted for 343.3 and 17.73 mg/kg for i.v. and p.o. routes, respectively). Our results demonstrate that using the tritium labeling technique enabled successful pharmacokinetic studies on polyphenolic drugs with very different molecular compositions. It proved to be efficient for tissue distribution studies. It was also shown that the dosage of the polyphenolic drug might be lower than 10 mg/kg due to the sensitivity of the 3H detection technique.

Supramolecular dimerization of a hexameric hemoprotein via multiple pyrene-pyrene interactions

2020 ◽  
Vol 24 (01n03) ◽  
pp. 259-267 ◽  
Author(s):  
Koji Oohora ◽  
Shota Hirayama ◽  
Tsuyoshi Mashima ◽  
Takashi Hayashi
Keyword(s):  
Supramolecular Assembly ◽  
Size Exclusion ◽  
Bottom Surface ◽  
Stacking Interactions ◽  
Protein Assemblies ◽  
New Class ◽  
Exclusion Chromatography ◽  
A Site ◽  
Subsequent Addition ◽  
Multivalent Effect

Protein assemblies are being investigated as a new-class of biomaterials. A supramolecular assembly of a mutant hexameric tyrosine coordinated hemoprotein (HTHP) modified with a pyrene derivative is described. Cysteine was first introduced as a site-specific reaction point at position V44 which is located at the bottom surface of the cylindrical structure of HTHP. [Formula: see text]-(1-pyrenyl)maleimide was then reacted with the mutant. The modification was confirmed by MALDI-TOF mass spectrometry and UV-vis absorption spectroscopy, indicating that approximately 90% cysteine residues are attached via the pyrene derivative. Size exclusion chromatography (SEC) measurements for pyrene-attached HTHP include a single peak which elutes earlier than the unmodified HTHP. Further investigation by SEC and dynamic light scattering (DLS) measurements indicate the desired size corresponding to the dimer of the hemoprotein hexamers. The multivalent effect of pyrene–pyrene interactions including hydrophobic and [Formula: see text]–[Formula: see text] stacking interactions appears to be responsible for including formation of the stable dimer of the hexamers. Interestingly, the assembly dissociates to the hexamer by removal of heme. In the case of the apo-form of pyrene-attached HTHP, the pyrene moiety appears to be incorporated into the heme pocket because the modification point is located at the adjacent residue of the Tyr45 coordinating to heme in the holo-form of HTHP. Subsequent addition of heme into the apo-form of pyrene-attached HTHP regenerates the dimer of the hexamers. The present study demonstrates a unique heme-dependent system in which HTHP is assembled to form a dimer of hexamers in the presence of heme and disassembled by removal of heme.

CHARACTERIZATION OF A NEW LCAT MUTATION CAUSING FAMILIAL LCAT DEFICIENCY (FLD) AND THE ROLE OF APOE AS A MODIFIER GENE OF THE FLD PHENOTYPE

2009 ◽  
Vol 32 (6S) ◽  
pp. 3
Author(s):  
A Baass ◽  
H Wassef ◽  
M Tremblay ◽  
L Bernier ◽  
R Dufour ◽  
...  
Keyword(s):  
Modifier Gene ◽  
Size Exclusion ◽  
Plasma Lipoproteins ◽  
Lipoprotein Profile ◽  
Exclusion Chromatography ◽  
Low Hdl ◽  
Lcat Deficiency ◽  
Apoe Genotypes

Introduction: LCAT (lecithin:cholesterol acyltransferase ) is an enzyme which plays an essential role in cholesterol esterification and reverse cholesterol transport. Familial LCAT deficiency (FLD) is a disease characterized by a defect in LCAT resulting in extremely low HDL-C, premature corneal opacities, anemia as well as proteinuria and renal failure. Method: We have identified two brothers presenting characteristics of familial LCAT deficiency. We sequenced the LCAT gene, measured the lipid profile as well as the LCAT activity in 15 members of this kindred. We also characterized the plasma lipoproteins by agarose gel electrophoresis and size exclusion chromatography and sequenced several candidate genes related to dysbetalipoproteinemia in this family. Results: We have identified the first French Canadian kindred with familial LCAT deficiency. Two brothers affected by FLD, were homozygous for a novel LCAT mutation. This c.102delG mutation occurs at the codon for His35 causing a frameshift that stops transcription at codon 61 abolishing LCAT enzymatic activity both in vivo and in vitro. It has a dramatic effect on the lipoprotein profile, with an important reduction of HDL-C in both heterozygotes (22%) and homozygotes (88%) and a significant decrease in LDL-C in heterozygotes (35%) as well as homozygotes (58%). Furthermore, the lipoprotein profile differed markedly between the two affected brothers who had different APOE genotypes. We propose that APOE could be an important modifier gene explaining heterogeneity in lipoprotein profiles observed among FLD patients. Our results suggest that a LCAT-/- genotype associated with an APOE ?2 allele could be a novel mechanism leading to dysbetalipoproteinemia.

Structure of a shear-thickening polysaccharide extracted from the New Zealand black tree fern, Cyathea medullaris

2020 ◽  
Author(s):  
M Wee ◽  
M Mastrangelo ◽  
Susan Carnachan ◽  
Ian Sims ◽  
K Goh
Keyword(s):  
New Zealand ◽  
Uronic Acid ◽  
Average Molecular Weight ◽  
Shear Thickening ◽  
Water Soluble ◽  
Size Exclusion ◽  
Resonance Spectroscopy ◽  
Tree Fern ◽  
13C Nuclear Magnetic Resonance ◽  
Exclusion Chromatography

A shear-thickening water-soluble polysaccharide was purified from mucilage extracted from the fronds of the New Zealand black tree fern (Cyathea medullaris or 'mamaku' in Māori) and its structure characterised. Constituent sugar analysis by three complementary methods, combined with linkage analysis (of carboxyl reduced samples) and 1H and 13C nuclear magnetic resonance spectroscopy (NMR) revealed a glucuronomannan comprising a backbone of 4-linked methylesterified glucopyranosyl uronic acid and 2-linked mannopyranosyl residues, branched at O-3 of 45% and at both O-3 and O-4 of 53% of the mannopyranosyl residues with side chains likely comprising terminal xylopyranosyl, terminal galactopyranosyl, non-methylesterified terminal glucopyranosyl uronic acid and 3-linked glucopyranosyl uronic acid residues. The weight-average molecular weight of the purified polysaccharide was ~1.9×106Da as determined by size-exclusion chromatography coupled with multi-angle laser light scattering (SEC-MALLS). The distinctive rheological properties of this polysaccharide are discussed in relation to its structure. © 2014 Elsevier B.V.

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