scholarly journals Phoneutria nigriventer Spider Toxin PnTx2-1 (δ-Ctenitoxin-Pn1a) Is a Modulator of Sodium Channel Gating

Toxins ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 337 ◽  
Author(s):  
Steve Peigneur ◽  
Ana Paiva ◽  
Marta Cordeiro ◽  
Márcia Borges ◽  
Marcelo Diniz ◽  
...  
Keyword(s):  
Clinical Manifestations ◽  
Biologically Active ◽  
Active Components ◽  
Efficient Treatment ◽  
Venom Composition ◽  
Voltage Gated Sodium Channels ◽  
Comprehensive Knowledge ◽  
Electrophysiological Characterization ◽  
Phoneutria Nigriventer

Spider venoms are complex mixtures of biologically active components with potentially interesting applications for drug discovery or for agricultural purposes. The spider Phoneutria nigriventer is responsible for a number of envenomations with sometimes severe clinical manifestations in humans. A more efficient treatment requires a comprehensive knowledge of the venom composition and of the action mechanism of the constituting components. PnTx2-1 (also called δ-ctenitoxin-Pn1a) is a 53-amino-acid-residue peptide isolated from the venom fraction PhTx2. Although PnTx2-1 is classified as a neurotoxin, its molecular target has remained unknown. This study describes the electrophysiological characterization of PnTx2-1 as a modulator of voltage-gated sodium channels. PnTx2-1 is investigated for its activity on seven mammalian NaV-channel isoforms, one insect NaV channel and one arachnid NaV channel. Furthermore, comparison of the activity of both PnTx2-1 and PnTx2-6 on NaV1.5 channels reveals that this family of Phoneutria toxins modulates the cardiac NaV channel in a bifunctional manner, resulting in an alteration of the inactivation process and a reduction of the sodium peak current.

Purification and characterization of tuberculin-active components from BCG

1975 ◽  
Vol 21 (12) ◽  
pp. 2019-2027
Author(s):  
M. Laguerre ◽  
R. Turcotte
Keyword(s):  
Physicochemical Properties ◽  
Guinea Pigs ◽  
Gel Filtration ◽  
Biologically Active ◽  
Polyacrylamide Gels ◽  
Active Components ◽  
Purification And Characterization ◽  
Molecular Weights ◽  
Antigenic Activity

The tuberculin activity of protoplasmic extracts isolated from living BCG was purified successively by gel filtration on Sephadex G-100 and G-75, and by electrophoresis on 7.5% and on gradient (6–18%) polyacrylamide gels. The tuberculin-active fractions, as determined in BCG-sensitized guinea pigs, were used as the starting material for each of the following fractionation steps.The physicochemical properties and the antigenic activity of the biologically active fractions have shown that a single component, or only a few ones with similar properties, possessed high tuberculin activity. These active components were proteins having relatively high molecular weights (about 72 000) and could behave as antigens.

scholarly journals Characterization of Polyphenolic Compounds in Cantaloupe Melon By-Products

Foods ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 196 ◽  
Author(s):  
Filomena Monica Vella ◽  
Domenico Cautela ◽  
Bruna Laratta
Keyword(s):  
Biochemical Characterization ◽  
Animal Feed ◽  
Natural Antioxidants ◽  
Positive Influence ◽  
Biologically Active ◽  
Active Components ◽  
Potential Benefits ◽  
Pharmaceutical Industries ◽  
By Products

The Muskmelon (Cucumis melo L.), which includes several crops of great economic importance worldwide, belongs to the Cucurbitaceae family, and it is well recognized for culinary and medicinal purposes. The high fruit consumption produces a large quantity of waste materials, such as peels and seeds that are still rich in molecules like polyphenols, carotenoids, and other biologically active components that possess a positive influence on human health and wellness. A sustainable development in agro-food and agro-industry sectors could come through the reutilization and valorization of these wastes, which in turn, could result in reducing their environmental impact. The current study provides a biochemical characterization of cantaloupe by-products, peels and seeds, through evaluating total polyphenols, ortho-diphenols, flavonoids, and tannins content. Furthermore, the antioxidant activity was assessed in order to understand potential benefits as natural antioxidants. Overall, the peel extract revealed the highest radical’s scavenging and reducing activities, moreover, it showed higher polyphenolic content than seed extract as revealed by both cromatographic and spectrophotometric analyses. The results of the present study indicate that the melon residues are a good source of natural phytochemicals useful for many purposes, such as ingredients for nutraceutic, cosmetic, or pharmaceutical industries, development of functional ingredients and new foods, and production of fertilizers and animal feed.

Characterization of photosystem II with the atomic-force microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1146-1147
Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon
Keyword(s):  
Photosystem Ii ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Biologically Active ◽  
Atomic Force ◽  
Freeze Etching ◽  
Image Averaging ◽  
Oxygen Evolving ◽  
Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

Clinical and molecular cytogenetic characterization of two cases of inverted duplication deletion 8p

2020 ◽  
pp. 41-42
Author(s):  
Д.А. Юрченко ◽  
М.Е. Миньженкова ◽  
Е.Л. Дадали ◽  
Н.В. Шилова
Keyword(s):  
Mental Retardation ◽  
Congenital Heart ◽  
Heart Defects ◽  
Clinical Manifestations ◽  
Formation Mechanisms ◽  
Agenesis Of Corpus Callosum ◽  
Molecular Cytogenetic ◽  
Inverted Duplication ◽  
Cytogenetic Characterization

Синдром инвертированной дупликации короткого плеча хромосомы 8 со смежной терминальной делециенй (inv dup del(8p), ORPHA 96092) - редкая хромосомная аномалия (ХА) с частотой 1/10000-1/30000 живорожденных. В статье представлены клинические и молекулярно-цитогенетические характеристики двух неродственных пациентов с синдромом inv dup del(8p) и уточнены механизмы формирования хромосомного дисбаланса. Inverted duplication deletion 8p syndrome (inv dup del(8p), ORPHA 96092) is a rare chromosomal abnormality with a frequency of 1:10,000 - 30,000 newborns. Clinical manifestations of this syndrome include mental retardation, facial anomalies, hypoplasia/agenesis of corpus callosum, scoliosis and/or kyphosis, hypotonia, congenital heart defects. The article presents the clinical and molecular cytogenetic characteristics of two patients with inv dup del (8p) syndrome and clarifies the formation mechanisms.

Electrophysiological Characterization of Transport Across Outer Membrane Channels from Gram-Negative Bacteria in Their Native Environment

2019 ◽  
Author(s):  
Jiajun Wang ◽  
Rémi Terrasse ◽  
Jayesh Arun Bafna ◽  
Lorraine Benier ◽  
Mathias Winterhalter
Keyword(s):  
Outer Membrane ◽  
Lipid Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Multi Drug Resistance ◽  
Gram Negative Bacteria ◽  
Membrane Channels ◽  
Gram Negative ◽  
Electrophysiological Characterization

Multi-drug resistance in Gram-negative bacteria is often associated with low permeability of the outer membrane. To investigate the role of membrane channels in the uptake of antibiotics, we extract, purify and reconstitute them into artificial planar membranes. To avoid this time-consuming procedure, here we show a robust approach using fusion of native outer membrane vesicles (OMV) into planar lipid bilayer which moreover allows also to some extend the characterization of membrane protein channels in their native environment. Two major membrane channels from <i>Escherichia coli</i>, OmpF and OmpC, were overexpressed from the host and the corresponding OMVs were collected. Each OMV fusion revealed surprisingly single or only few channel activities. The asymmetry of the OMV´s translates after fusion into the lipid membrane with the LPS dominantly present at the side of OMV addition. Compared to conventional reconstitution methods, the channels fused from OMVs containing LPS have similar conductance but a much broader distribution. The addition of Enrofloxacin on the LPS side yields somewhat higher association (<i>k<sub>on</sub></i>) and lower dissociation (<i>k<sub>off</sub></i>) rates compared to LPS-free reconstitution. We conclude that using outer membrane vesicles is a fast and easy approach for functional and structural studies of membrane channels in the native membrane.

PRODUCTION OF BLENDED JUICE FROM PUMPKIN, QUINCE, PERSIMMON

2018 ◽  
pp. 59-62
Author(s):  
I. A. Kyazimova ◽  
А. А. Kasumova ◽  
А. А. Nabiev
Keyword(s):  
Phenolic Compounds ◽  
Organic Acids ◽  
New Technology ◽  
Mineral Elements ◽  
Biologically Active ◽  
Active Components ◽  
Aliphatic Acids ◽  
Free Glucose ◽  
Dietary Value ◽  
Quantitative Indicators

Production of plant products, including juices around the world increases continuously. In the fruit and vegetable juices contain a significant amount of monosaccharides (glucose and fructose), organic acids, vitamins, phenolic compounds, mineral substances and other biologically active components that determine the nutritional and dietary value. For the prevention of various diseases associated with impaired metabolic processes, we developed a new technology of preparation of food by blending juice of pumpkin, quince and persimmon. Thus prepared organic blended juice contains a substantial amount of free glucose and fructose, different phenolic compounds, a sufficient amount of organic acids, mineral elements, including iodine and other components that determine its nutritional and biological value. In prepared juices were evaluated the quantitative indicators of β-carotene, vitamin C, glucose and fructose, sucrose, starch, pectin substances. Also in the atomic absorbtion spectrometer Analyst 400 (PerkinElmer, USA) was analyzed content of the organic acids and phenolic compounds. Prepared juices were tested in accordance with 10 point scoring scale. It is established that all juices contain a sufficient amount of the minerals. In pumpkin and quince juices not contain iodine while it presents in sufficient amount in persimmon juice that’s why in the blended juice mineral in addition to mineral elements iodine are contained. In pumpkin and persimmon aliphatic acids are contained in small amount. For this reason during the blending process was used quince juice which is rich in aliphatic acids. The blended juice is light straw color, with delicious flavor, a slight astringent property and a balanced taste.

Characterization of Biologically Active Substances from Calendula officinalis

2018 ◽  
Vol 18 (14) ◽  
pp. 1167-1174 ◽  
Author(s):  
Petra Lovecka ◽  
Jan Lipov ◽  
Kamila Thumova ◽  
Anna Macurkova
Keyword(s):  
Biologically Active Substances ◽  
Biologically Active ◽  
Calendula Officinalis ◽  
Active Substances

scholarly journals Hepatoprotective Effect of Mixture of Dipropyl Polysulfides in Concanavalin A-Induced Hepatitis

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 1022
Author(s):  
Dragana Arsenijevic ◽  
Bojana Stojanovic ◽  
Jelena Milovanovic ◽  
Aleksandar Arsenijevic ◽  
Milos Simic ◽  
...  
Keyword(s):  
Concanavalin A ◽  
Messenger Rna ◽  
T Regulatory Cells ◽  
Mononuclear Cells ◽  
Biological Activities ◽  
Biologically Active ◽  
Organosulfur Compounds ◽  
Liver Inflammation ◽  
Regulatory Cells ◽  
Active Components

The main biologically active components of plants belonging to the genus Allium, responsible for their biological activities, including anti-inflammatory, antioxidant and immunomodulatory, are organosulfur compounds. The aim of this study was to synthetize the mixture of dipropyl polysulfides (DPPS) and to test their biological activity in acute hepatitis. C57BL/6 mice were administered orally with DPPS 6 h before intravenous injection of Concanavalin A (ConA). Liver inflammation, necrosis and hepatocytes apoptosis were determined by histological analyses. Cytokines in liver tissue were determined by ELISA, expression of adhesive molecules and enzymes by RT PCR, while liver mononuclear cells were analyzed by flow cytometry. DPPS pretreatment significantly attenuated liver inflammation and injury, as evidenced by biochemical and histopathological observations. In DPPS-pretreated mice, messenger RNA levels of adhesion molecules and NADPH oxidase complex were significantly reduced, while the expression of SOD enzymes was enhanced. DPPS pretreatment decreased protein level of inflammatory cytokines and increased percentage of T regulatory cells in the livers of ConA mice. DPPS showed hepatoprotective effects in ConA-induced hepatitis, characterized by attenuation of inflammation and affection of Th17/Treg balance in favor of T regulatory cells and implicating potential therapeutic usage of DPPS mixture in inflammatory liver diseases.

scholarly journals Electrophysiological characterization of a diverse group of sugar transporters from Trichoderma reesei

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sami Havukainen ◽  
Jonai Pujol-Giménez ◽  
Mari Valkonen ◽  
Ann Westerholm-Parvinen ◽  
Matthias A. Hediger ◽  
...  
Keyword(s):  
Trichoderma Reesei ◽  
Scientific Literature ◽  
Large Body ◽  
Comprehensive Analysis ◽  
Transport Function ◽  
Sugar Transporters ◽  
New Knowledge ◽  
Electrophysiological Characterization ◽  
Shed Light

AbstractTrichoderma reesei is an ascomycete fungus known for its capability to secrete high amounts of extracellular cellulose- and hemicellulose-degrading enzymes. These enzymes are utilized in the production of second-generation biofuels and T. reesei is a well-established host for their production. Although this species has gained considerable interest in the scientific literature, the sugar transportome of T. reesei remains poorly characterized. Better understanding of the proteins involved in the transport of different sugars could be utilized for engineering better enzyme production strains. In this study we aimed to shed light on this matter by characterizing multiple T. reesei transporters capable of transporting various types of sugars. We used phylogenetics to select transporters for expression in Xenopus laevis oocytes to screen for transport activities. Of the 18 tested transporters, 8 were found to be functional in oocytes. 10 transporters in total were investigated in oocytes and in yeast, and for 3 of them no transport function had been described in literature. This comprehensive analysis provides a large body of new knowledge about T. reesei sugar transporters, and further establishes X. laevis oocytes as a valuable tool for studying fungal sugar transporters.

Sign in / Sign up

Export Citation Format

Share Document