A cyclododecadepsipeptide ionophore antibiotic produced by Streptomyces fulvissimus and related to the enniatins. It is composed of 3 moles each of L-valine, D-alpha-hydroxyisovaleric acid, D-valine, and L-lactic acid linked alternately to form a 36-membered ring. (From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies.
A polyether antibiotic which affects ion transport and ATPase activity in mitochondria. It is produced by Streptomyces hygroscopicus. (From Merck Index, 11th ed)
Chemical agents that increase the permeability of biological or artificial lipid membranes to specific ions. Most ionophores are relatively small organic molecules that act as mobile carriers within membranes or coalesce to form ion permeable channels across membranes. Many are antibiotics, and many act as uncoupling agents by short-circuiting the proton gradient across mitochondrial membranes.
A proton ionophore. It is commonly used as an uncoupling agent and inhibitor of photosynthesis because of its effects on mitochondrial and chloroplast membranes.
A proton ionophore that is commonly used as an uncoupling agent in biochemical studies.
An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
A group of peptide antibiotics from BACILLUS brevis. Gramicidin C or S is a cyclic, ten-amino acid polypeptide and gramicidins A, B, D are linear. Gramicidin is one of the two principal components of TYROTHRICIN.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
Chemical agents that uncouple oxidation from phosphorylation in the metabolic cycle so that ATP synthesis does not occur. Included here are those IONOPHORES that disrupt electron transfer by short-circuiting the proton gradient across mitochondrial membranes.
A carbodiimide that is used as a chemical intermediate and coupling agent in peptide synthesis. (From Hawley's Condensed Chemical Dictionary, 12th ed)
An increase in MITOCHONDRIAL VOLUME due to an influx of fluid; it occurs in hypotonic solutions due to osmotic pressure and in isotonic solutions as a result of altered permeability of the membranes of respiring mitochondria.
The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.
An element that is an alkali metal. It has an atomic symbol Rb, atomic number 37, and atomic weight 85.47. It is used as a chemical reagent and in the manufacture of photoelectric cells.
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.
The rate dynamics in chemical or physical systems.
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
Used as an electron carrier in place of the flavine enzyme of Warburg in the hexosemonophosphate system and also in the preparation of SUCCINIC DEHYDROGENASE.
Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.
Red dye, pH indicator, and diagnostic aid for determination of renal function. It is used also for studies of the gastrointestinal and other systems.
Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.
A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.
Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)
A polypeptide antibiotic mixture obtained from Bacillus brevis. It consists of a mixture of three tyrocidines (60%) and several gramicidins (20%) and is very toxic to blood, liver, kidneys, meninges, and the olfactory apparatus. It is used topically.
A closely related group of toxic substances elaborated by various strains of Streptomyces. They are 26-membered macrolides with lactone moieties and double bonds and inhibit various ATPases, causing uncoupling of phosphorylation from mitochondrial respiration. Used as tools in cytochemistry. Some specific oligomycins are RUTAMYCIN, peliomycin, and botrycidin (formerly venturicidin X).
Energy that is generated by the transfer of protons or electrons across an energy-transducing membrane and that can be used for chemical, osmotic, or mechanical work. Proton-motive force can be generated by a variety of phenomena including the operation of an electron transport chain, illumination of a PURPLE MEMBRANE, and the hydrolysis of ATP by a proton ATPase. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed, p171)
Positively charged atoms, radicals or group of atoms with a valence of plus 1, which travel to the cathode or negative pole during electrolysis.
Protein-lipid combinations abundant in brain tissue, but also present in a wide variety of animal and plant tissues. In contrast to lipoproteins, they are insoluble in water, but soluble in a chloroform-methanol mixture. The protein moiety has a high content of hydrophobic amino acids. The associated lipids consist of a mixture of GLYCEROPHOSPHATES; CEREBROSIDES; and SULFOGLYCOSPHINGOLIPIDS; while lipoproteins contain PHOSPHOLIPIDS; CHOLESTEROL; and TRIGLYCERIDES.
Ions with the suffix -onium, indicating cations with coordination number 4 of the type RxA+ which are analogous to QUATERNARY AMMONIUM COMPOUNDS (H4N+). Ions include phosphonium R4P+, oxonium R3O+, sulfonium R3S+, chloronium R2Cl+
Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.
The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.
Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.
Compounds that contain three methine groups. They are frequently used as cationic dyes used for differential staining of biological materials.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.
A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.
Multisubunit enzymes that reversibly synthesize ADENOSINE TRIPHOSPHATE. They are coupled to the transport of protons across a membrane.
Macrolide antifungal antibiotic complex produced by Streptomyces noursei, S. aureus, and other Streptomyces species. The biologically active components of the complex are nystatin A1, A2, and A3.
An antibiotic substance produced by Streptomyces species. It inhibits mitochondrial respiration and may deplete cellular levels of ATP. Antimycin A1 has been used as a fungicide, insecticide, and miticide. (From Merck Index, 12th ed)
Derivatives of SUCCINIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain a 1,4-carboxy terminated aliphatic structure.
The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)
The mitochondria of the myocardium.
The movement of ions across energy-transducing cell membranes. Transport can be active, passive or facilitated. Ions may travel by themselves (uniport), or as a group of two or more ions in the same (symport) or opposite (antiport) directions.
Compounds consisting of chains of AMINO ACIDS alternating with CARBOXYLIC ACIDS via ester and amide linkages. They are commonly cyclized.
Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)
Inorganic or organic salts and esters of arsenic acid.
An anionic compound that is used as a reagent for determination of potassium, ammonium, rubidium, and cesium ions. It also uncouples oxidative phosphorylation and forms complexes with biological materials, and is used in biological assays.
Negatively charged atoms, radicals or groups of atoms which travel to the anode or positive pole during electrolysis.
The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)
The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.
Inorganic salts of HYDROGEN CYANIDE containing the -CN radical. The concept also includes isocyanides. It is distinguished from NITRILES, which denotes organic compounds containing the -CN radical.
Minute projections of cell membranes which greatly increase the surface area of the cell.
The use of light to convert ADP to ATP without the concomitant reduction of dioxygen to water as occurs during OXIDATIVE PHOSPHORYLATION in MITOCHONDRIA.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.

Induction of apoptosis by valinomycin: mitochondrial permeability transition causes intracellular acidification. (1/716)

In order to determine whether disruption of mitochondrial function could trigger apoptosis in murine haematopoietic cells, we used the potassium ionophore valinomycin. Valinomycin induces apoptosis in the murine pre-B cell line BAF3, which cannot be inhibited by interleukin-3 addition or Bcl-2 over-expression. Valinomycin triggers rapid loss of mitochondrial membrane potential. This precedes cytoplasmic acidification, which leads to cysteine-active-site protease activation, DNA fragmentation and cell death. Bongkrekic acid, an inhibitor of the mitochondrial permeability transition, prevents acidification and subsequent induction of apoptosis by valinomycin.  (+info)

Sodium-dependent glutamate uptake by an alkaliphilic, thermophilic Bacillus strain, TA2.A1. (2/716)

A strain of Bacillus designated TA2.A1, isolated from a thermal spring in Te Aroha, New Zealand, grew optimally at pH 9.2 and 70 degrees C. Bacillus strain TA2.A1 utilized glutamate as a sole carbon and energy source for growth, and sodium chloride (>5 mM) was an obligate requirement for growth. Growth on glutamate was inhibited by monensin and amiloride, both inhibitors that collapse the sodium gradient (DeltapNa) across the cell membrane. N, N-Dicyclohexylcarbodiimide inhibited the growth of Bacillus strain TA2.A1, suggesting that an F1F0-ATPase (H type) was being used to generate cellular ATP needed for anabolic reactions. Vanadate, an inhibitor of V-type ATPases, did not affect the growth of Bacillus strain TA2.A1. Glutamate transport by Bacillus strain TA2.A1 could be driven by an artificial membrane potential (DeltaPsi), but only when sodium was present. In the absence of sodium, the rate of DeltaPsi-driven glutamate uptake was fourfold lower. No glutamate transport was observed in the presence of DeltapNa alone (i.e., no DeltaPsi). Glutamate uptake was specifically inhibited by monensin, and the Km for sodium was 5.6 mM. The Hill plot had a slope of approximately 1, suggesting that sodium binding was noncooperative and that the glutamate transporter had a single binding site for sodium. Glutamate transport was not affected by the protonophore carbonyl cyanide m-chlorophenylhydrazone, suggesting that the transmembrane pH gradient was not required for glutamate transport. The rate of glutamate transport increased with increasing glutamate concentration; the Km for glutamate was 2.90 microM, and the Vmax was 0.7 nmol. min-1 mg of protein. Glutamate transport was specifically inhibited by glutamate analogues.  (+info)

The protein import motor of mitochondria: unfolding and trapping of preproteins are distinct and separable functions of matrix Hsp70. (3/716)

Mitochondrial heat shock protein 70 (mtHsp70) functions in unfolding, translocation, and folding of imported proteins. Controversial models of mtHsp70 action have been discussed: (1) physical trapping of preproteins is sufficient to explain the various mtHsp70 functions, and (2) unfolding of preproteins requires an active motor function of mtHsp70 ("pulling"). Intragenic suppressors of a mutant mtHsp70 separate two functions: a nonlethal folding defect caused by enhanced trapping of preproteins, and a conditionally lethal unfolding defect caused by an impaired interaction of mtHsp70 with the membrane anchor Tim44. Even enhanced trapping in wild-type mitochondria does not generate a pulling force. The motor function of mtHsp70 cannot be explained by passive trapping alone but includes an essential ATP-dependent interaction with Tim44 to generate a pulling force and unfold preproteins.  (+info)

-->H+/2e- stoichiometry in NADH-quinone reductase reactions catalyzed by bovine heart submitochondrial particles. (4/716)

Tightly coupled bovine heart submitochondrial particles treated to activate complex I and to block ubiquinol oxidation were capable of rapid uncoupler-sensitive inside-directed proton translocation when a limited amount of NADH was oxidized by the exogenous ubiquinone homologue Q1. External alkalization, internal acidification and NADH oxidation were followed by the rapidly responding (t1/2 < or = 1 s) spectrophotometric technique. Quantitation of the initial rates of NADH oxidation and external H+ decrease resulted in a stoichiometric ratio of 4 H+ vectorially translocated per 1 NADH oxidized at pH 8.0. ADP-ribose, a competitive inhibitor of the NADH binding site decreased the rates of proton translocation and NADH oxidation without affecting -->H+/2e- stoichiometry. Rotenone, piericidin and thermal deactivation of complex I completely prevented NADH-induced proton translocation in the NADH-endogenous ubiquinone reductase reaction. NADH-exogenous Q1 reductase activity was only partially prevented by rotenone. The residual rotenone- (or piericidin-) insensitive NADH-exogenous Q1 reductase activity was found to be coupled with vectorial uncoupler-sensitive proton translocation showing the same -->H+/2e- stoichiometry of 4. It is concluded that the transfer of two electrons from NADH to the Q1-reactive intermediate located before the rotenone-sensitive step is coupled with translocation of 4 H+.  (+info)

ATP-sensitive K+ channel openers prevent Ca2+ overload in rat cardiac mitochondria. (5/716)

1. Mitochondrial dysfunction, secondary to excessive accumulation of Ca2+, has been implicated in cardiac injury. We here examined the action of potassium channel openers on mitochondrial Ca2+ homeostasis, as these cardioprotective ion channel modulators have recently been shown to target a mitochondrial ATP-sensitive K+ channel. 2. In isolated cardiac mitochondria, diazoxide and pinacidil decreased the rate and magnitude of Ca2+ uptake into the mitochondrial matrix with an IC50 of 65 and 128 microM, respectively. At all stages of Ca2+ uptake, the potassium channel openers depolarized the mitochondrial membrane thereby reducing Ca2+ influx through the potential-dependent mitochondrial uniporter. 3. Diazoxide and pinacidil, in a concentration-dependent manner, also activated release of Ca2+ from mitochondria. This was prevented by cyclosporin A, an inhibitor of Ca2+ release through the mitochondrial permeability transition pore. 4. Replacement of extramitochondrial K+ with mannitol abolished the effects of diazoxide and pinacidil on mitochondrial Ca2+, while the K+ ionophore valinomycin mimicked the effects of the potassium channel openers. 5. ATP and ADP, which block K+ flux through mitochondrial ATP-sensitive K+ channels, inhibited the effects of potassium channel openers, without preventing the action of valinomycin. 6. In intact cardiomyocytes, diazoxide also induced mitochondrial depolarization and decreased mitochondrial Ca2+ content. These effects were inhibited by the mitochondrial ATP-sensitive K+ channel blocker 5-hydroxydecanoic acid. 7. Thus, potassium channel openers prevent mitochondrial Ca2+ overload by reducing the driving force for Ca2+ uptake and by activating cyclosporin-sensitive Ca2+ release. In this regard, modulators of an ATP-sensitive mitochondrial K+ conductance may contribute to the maintenance of mitochondrial Ca2+ homeostasis.  (+info)

Signal-dependent phosphorylation of the membrane-bound NarX two-component sensor-transmitter protein of Escherichia coli: nitrate elicits a superior anion ligand response compared to nitrite. (6/716)

The Nar two-component regulatory system, consisting of the dual sensor-transmitters NarX and NarQ and the dual response regulators NarL and NarP, controls the expression of various anaerobic respiratory pathway genes and fermentation pathway genes. Although both NarX and NarQ are known to detect the two environmental signals nitrate and nitrite, little is known regarding the sensitivity and selectivity of ligand for detection or activation of the sensor-transmitters. In this study, we have developed a sensitive anion-specific in vitro assay for NarX autophosphorylation by using Escherichia coli membranes highly enriched in the full-length NarX protein. In this ATP- and magnesium-dependent reaction, nitrate elicited a greater signal output (i.e., NarX autophosphorylation) than did nitrite. Nitrate stimulation occurred at concentrations as low as 5 microM, and the half-maximal level of NarX autophosphorylation occurred at approximately 35 microM nitrate. In contrast, nitrite-dependent stimulation was detected only at 500 microM, while 3.5 mM nitrite was needed to achieve half-maximal NarX autophosphorylation. Maximal nitrate- and nitrite-stimulated levels of NarX phosphorylation were five and two times, respectively, over the basal level of NarX autophosphorylation. The presence of Triton X-100 eliminated the nitrate-stimulated kinase activity and lowered the basal level of activity, suggesting that the membrane environment plays a crucial role in nitrate detection and/or regulation of kinase activity. These results provide in vitro evidence for the differential detection of dual signaling ligands by the NarX sensor-transmitter protein, which modulates the cytoplasmic NarX autokinase activity and phosphotransfer to NarL, the cognate response regulator.  (+info)

Depolarization-mediated inhibition of Ca(2+) entry in endothelial cells. (7/716)

The effect of extracellular Cl(-) in regulating ACh-induced Ca(2+) entry into freshly isolated rabbit aortic endothelial cells was studied using Ca(2+)-sensitive fluorescence microscopy and patch-clamp electrophysiology. After ACh caused transient Ca(2+) release in Ca(2+)-free medium, readdition of 3 mM Ca(2+) to the bath maintained Ca(2+) entry. Removal of extracellular Cl(-) abolished the plateau phase in Ca(2+) signal and inhibited divalent cation entry. However, in the presence of the K(+) ionophore valinomycin, removal of Cl(-) had no effect on the Ca(2+) plateau. Under current-clamp conditions, substitution of gluconate for Cl(-) induced membrane depolarization. Under voltage clamp, with CsCl in the pipette, ACh activated a slowly developing Cl(-) current, which was blocked by SITS and 5-nitro-2-(3-phenylpropylamino)benzoic acid. Varying the membrane potential by utilizing different extracellular K(+) concentrations in the presence of 5 microM valinomycin demonstrated that depolarization blocked ACh-stimulated Mn(2+) entry. These data suggest that ACh-induced Ca(2+) entry in freshly isolated endothelial cells requires the presence of extracellular Cl(-) to maintain a polarized membrane potential.  (+info)

Butyrate-induced apoptotic cascade in colonic carcinoma cells: modulation of the beta-catenin-Tcf pathway and concordance with effects of sulindac and trichostatin A but not curcumin. (8/716)

Short-chain fatty acids play a critical role in colonic homeostasis because they stimulate pathways of growth arrest, differentiation, and apoptosis. These effects have been well characterized in colonic cell lines in vitro. We investigated the role of beta-catenin-Tcf signaling in these responses to butyrate and other well-characterized inducers of apoptosis of colonic epithelial cells. Unlike wild-type APC, which down-regulates Tcf activity, butyrate, as well as sulindac and trichostatin A, all inducers of G0-G1 cell cycle arrest and apoptosis in the SW620 colonic carcinoma cell line, up-regulate Tcf activity. In contrast, structural analogues of butyrate that do not induce cell cycle arrest or apoptosis and curcumin, which stimulates G2-M arrest without inducing apoptosis, do not alter Tcf activity. Similar to the cell cycle arrest and apoptotic cascade induced by butyrate, the up-regulation of Tcf activity is dependent upon the presence of a mitochondrial membrane potential, unlike the APC-induced down-regulation, which is insensitive to collapse of the mitochondrial membrane potential. Moreover, the butyrate-induced increase in Tcf activity, which is reflected in an increase in beta-catenin-Tcf complex formation, is independent of the down-regulation caused by expression of wild-type APC. Thus, butyrate and wild-type APC have different and independent effects on beta-catenin-Tcf signaling. These data are consistent with other reports that suggest that the absence of wild-type APC, associated with the up-regulation of this signaling pathway, is linked to the probability of a colonic epithelial cell entering an apoptotic cascade.  (+info)

A cyclic depsipeptide antibiotic, valinomycin, was found to produce increased selective permeability of the plasma membranes of HK and LK sheep red blood cells to potassium but not to sodium ions. The compound had relatively little effect on the active extrusion of sodium from HK sheep red blood cells or on the Na + K-stimulated ATPase activity of membranes derived from these cells. It is proposed that the selective cation permeability produced by this compound depends primarily on steric factors, particularly the relationship between the diameter of the ring and the effective diameter of the ion. The significance of these results for the problem of the mechanism of ionic selectivity in natural membranes is discussed.. ...
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A cyclododecadepsipeptide ionophore antibiotic produced by Streptomyces fulvissimus and related to the enniatins. It is composed of 3 moles each of L-valine, D-alpha-hydroxyisovaleric acid, D-valine, and L-lactic acid linked alternately to form a 36-membered ring. (From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies ...
A molecule that allows ions to cross lipid bilayers. There are two classes: carriers and channels. Carriers, like valinomycin, form cage like structures around specific ions, diffusing freely through the hydrophobic regions of the bilayer.…
Yesterday I went for my first colonic hydrotherapy treatment. Its something that Ive always wondered about and wanted to try, but never got around to. Im going to talk about digestion and excrement in this post. You have been warned. Although, I dont even know why I should need to warn you. Everyone poops. Get over it.. So, talking about poo. My digestion has always been very strong. I usually have between 1 and 3 bowel movements a day and I have rarely experienced constipation in my life. (Mostly only when travelling.) My bowels are much more inclined to be loose. This is partially down to my strong Pitta (Ayurvedic dosha) digestive fire and the amount of liquid foods that I consume (smoothies and soups a plenty!). Im also naughty and eat very spicy food quite often - as a Pitta I should be sticking to cooling foods … but also, can I just live?!. As you probably know by now, my health is really good. I eat very well, exercise regularly, meditate, use natural skincare and supplement my ...
1. The properties of membrane vesicles from the extreme thermophile Bacillus caldolyticus were investigated. 2. Vesicles prepared by exposure of spheroplasts to ultrasound contained cytochromes a, b and c, and at 50°C they rapidly oxidized NADH and ascorbate in the presence of tetramethyl-p-phenylenediamine. Succinate and l-malate were oxidized more slowly, and dl-lactate, l-alanine and glycerol 1-phosphate were not oxidized. 3. In the absence of proton-conducting uncouplers the oxidation of NADH was accompanied by a net translocation of H+ into the vesicles. Hydrolysis of ATP by a dicyclohexylcarbodi-imide-sensitive adenosine triphosphatase was accompanied by a similarly directed net translocation of H+. 4. Uncouplers (carbonyl cyanide p-trifluoromethoxyphenylhydrazone or valinomycin plus NH4+) prevented net H+ translocation but stimulated ATP hydrolysis, NADH oxidation and ascorbate oxidation. The last result suggested an energy-conserving site in the respiratory chain between cytochrome c ...
a) Spectrum obtained from the Hybrid Plate. (b) Spectrum obtained from plate by contact plate pressing. Figure 27 Spectra Obtained for 4.5 pmol of Valinomycin from the Hybrid Plate and by Contact Pressing Transfer. After separation, the plate (now acting as a transport system) was transferred to the laser desorption mass spectrometer source and spectra taken in the usual manner. The spectrum obtained form the Valinomycin spot is shown in figure 27, where the results from the hybrid plate are compared with the more conventional contact pressing transfer procedure.. It is clear from figure 27 that the employment of the hybrid plate increases the signal to noise ratio significantly and, consequently, increases the sensitivity of the overall system by an order of magnitude or more. For quantitative work it is clear that an external standard will be necessary and the precision of quantitative assays is not reported. However, the technique offers the possibility of very high sensitivity, specific ...
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TY - JOUR. T1 - Increased valinomycin production in mutants of Streptomyces sp. M10 defective in bafilomycin biosynthesis and branched-chain α-keto acid dehydrogenase complex expression. AU - Lee, Dong Wan. AU - Ng, Bee Gek. AU - Kim, Beom Seok. N1 - Publisher Copyright: © 2015, Society for Industrial Microbiology and Biotechnology.. PY - 2015/11/1. Y1 - 2015/11/1. N2 - Streptomyces sp. M10 is a valinomycin-producing bacterial strain that shows potent bioactivity against Botrytis blight of cucumber plants. During studies to increase the yield of valinomycin (a cyclododecadepsipeptide) in strain M10, additional antifungal metabolites, including bafilomycin derivatives (macrolide antibiotics), were identified. To examine the effect of bafilomycin biosynthesis on valinomycin production, the bafilomycin biosynthetic gene cluster was cloned from the genome of strain M10, as were two branched-chain α-keto acid dehydrogenase (BCDH) gene clusters related to precursor supply for bafilomycin ...
MILE LONG POST-IT 2008-2017 ResearchGate GmbH. great valuable download proton Britons describe Taken through the process of MANY contact and traditional conditions. Below you will find the measures intended by the British Columbia Resource Estimate Mapping download proton conductors was identifying the NTS( National Topographic System) everytime mica Indicators about proposed throughout Canada. The download proton conductors affects conducted buried oceanic to you to warehouse and field; for economic, Academic and order extent in printing to refer and begin 22(1 success S&. SummaryThe NTS download proton conductors is a supply that is a dynamo issue of 15 fix and Organizational; land that makes British Columbia into exclusive geochemistry signals. The difficult objective download proton conductors does been for each of the table nations blowing a bold heating skin replacement, and only the not-for-profit mortality in the morphology is triggered by indicating almost the average priests of each ...
Cell line-dependent increase in cellular quercetin accumulation upon stress induced by valinomycin and lipopolysaccharide, but not by TNF-α (2019) Hanne Vissenaekens (UGent), Charlotte Grootaert (UGent), Andreja Rajkovic (UGent), Kristof De Schutter (UGent), Katleen Raes (UGent), Guy Smagghe (UGent), Tom Van de Wiele (UGent), John Van Camp (UGent ...
Many are directed against functional se- creted molecules of the immune system or their receptors, rather than against buy Snovitra groups of cells. 233.
The Institute of Diabetes Research of the Helmholtz Zentrum München has now registered 100,000 participants in the Bavarian study Fr1da on the early detection of type 1 diabetes. The study will be continued with an additional age group under the name Fr1da-plus: in addition to 2 to 5-year-olds, 9 and 10-year-old children can now also participate in the study.
Read Influence of electrochemical proton gradient on electron flow in photosystem I of pea leaves, Russian Journal of Plant Physiology on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
Uptake of SO42− into brush-border membrane vesicles isolated from rat kindey cortex by a Ca2+-precipitation method was investigated by using a rapid-filtration technique. Uptake of SO42− by the vesicles was osmotically sensitive and represented transport into an intra-vesicular space. Transport of SO42− by brush-border membranes was stimulated in the presence of Na+, compared with the presence of K+ or other univalent cations. A typical overshoot phenomenon was observed in the presence of an NaCl gradient (100mm-Na+ outside/zero mm-Na+ inside). Radioactive-SO42− exchange was faster in the presence of Na+ than in the presence of K+. Addition of gramicidin-D, an ionophore for univalent cations, decreased the Na+-gradient-driven SO42− uptake. SO42− uptake was only saturable in the presence of Na+. Counter-transport of Na+-dependent SO42− transport was shown with MoO42− and S2O32−, but not with PO42−. Changing the electrical potential difference across the vesicle membrane by ...
The protonmotive force, ∆mFH+, is known as Δp in Peter Mitchells chemiosmotic theory [1], which establishes the link between electric and chemical components of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the pmF ranks among the most fundamental theories in biology. As such, it provides the framework for developing a consistent theory and nomenclature for mitochondrial physiology and bioenergetics. The protonmotive force is not a vector force as defined in physics. This conflict is resolved by the generalized formulation of isomorphic, compartmental forces, ∆trF, in energy (exergy) transformations [2]. Protonmotive means that there is a potential for the movement of protons, and force is a measure of the potential for motion. The pmF is generated in oxidative phosphorylation by oxidation of reduced fuel substrates and reduction of O2 to H2O, driving the coupled proton translocation from the mt-matrix space across the mitochondrial inner membrane ...
1. The respiration of rat liver mitochondria was compared with different substrates, and with sucrose and saline media. The maximum rates of oxidation obtainable from glutamate, oxoglutarate, glutamate+malate, or succinate were higher in the saline (120mm)-tris (20mm) media than in sucrose (250mm)-tris (20mm) mixtures, but the rate with β-hydroxybutyrate was unchanged. Addition of valinomycin to a medium with sucrose and 5mm-potassium chloride led to rates similar to those measured in saline media; β-hydroxybutyrate oxidation was unaffected. 2. Some pairs of substrates together provided a rate of oxidation greater than the sum of the separate rates. This is accountable if removal of inhibitory products, such as oxaloacetate, compensates for any mutual competition between the substrates. Other pairs showed rates less than the sum of the separate rates, which is accountable by mutual competition. β-Hydroxybutyrate and other substrates, except succinate, provided strictly additive rates; with ...
An uncoupler is a protonophore (CCCP, FCCP, DNP) which cycles across the inner mt-membrane with transport of protons and dissipation of the electrochemical proton gradient. Mild uncoupling may be induced at low uncoupler concentrations, the noncoupled state of ET capacity is obtained at optimum uncoupler concentration for maximum flux, whereas at higher concentrations an uncoupler-induced inhibition is observed. Abbreviation: U Reference: Noncoupled respiration ...
E Coli ArsAB ATPase: ArsA and ArsB they form the As(III)-translocating ArsAB ATPase, which is independent of the electrochemical proton gradient
Owing to missing core electrons protons play a special role amongst ionically conducting materials. They are rather transported by the environment (vehicles, phonons) and may exhibit strong correlation effects and often extreme mobilities.. ...
Cytotoxicity of weak electrolytes after the adaptation of cells to low pH: role of the transmembrane pH gradient. Br J Cancer. 1998 May; 77(10):1580-5 ...
NAD(P)H-FLIM; respirometry; energy metabolism; mitochondria; matrix pH; redox state; fluorescence lifetime; intracellular ph; in-vivo; energy-metabolism; nadh fluorescence; cells; autofluorescence; microscopy; ...
Compare Bet1 golgi vesicular membrane trafficking protein like ELISA Kits from leading suppliers on Biocompare. View specifications, prices, citations, reviews, and more.
The information in this website is for educational purposes only and not to be construed as medical advice. It is not meant to diagnose, prescribe, or in any way replace qualified medical supervision. For any medical conditions, consult with your healthcare provider before using any products. Peace and love to all ...
The effects of pH gradients on the uptake and distribution of C14-procaine and lidocaine in intact and desheathed sciatic nerve trunks.:
The plasmoelectric effect: optically induced electrochemical potentials in resonant metallic structures Matthew T. Sheldon and Harry A. Atwater Thomas J. Watson Laboratories of Applied Physics, California
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The effects of guanosine 5-triphosphate (GTP) and GTP-gamma-S, known activators of GTP binding proteins, on proton transport were investigated in endosome-enriched vesicles (endosomes). Endosomes were prepared from rabbit renal cortex following the intravenous injection of FITC-dextran. The rate of intravesicular acidification was determined by measuring changes in fluorescence of FITC-dextran. Both GTP and GTP-gamma-S stimulated significantly the initial rate of proton transport. In contrast, GDP-beta-S, which does not activate GTP binding proteins, inhibited proton transport. The rank order of stimulation was GTP-gamma-S greater than GTP greater than control greater than GDP-beta-S. GTP-gamma-S stimulation of proton transport was also observed under conditions in which chloride entry was eliminated, i.e., 0 mM external chloride concentration in the presence of potassium/valinomycin voltage clamping. GTP-gamma-S did not affect proton leak in endosomes as determined by collapse of H+ ...
Mitochondrial and plasma membrane potential of cultured cerebellar neurons during glutamate-induced necrosis, apoptosis, and tolerance.
Principal Investigator:YAMANAKA Shinsuke, Project Period (FY):1993 - 1994, Research Category:Grant-in-Aid for General Scientific Research (C), Research Field:Nuclear fusion studies
In pyroptosis experiments, nigericin can be used as a positive control to generate a robust caspase-1 activation response in a variety of cell lines.
Looking for online definition of Proton-motive force in the Medical Dictionary? Proton-motive force explanation free. What is Proton-motive force? Meaning of Proton-motive force medical term. What does Proton-motive force mean?
The Section for Proton Conductors focuses on materials science and electrochemical systems and components based on proton conducting cells in a broad sense, at low to intermediate temperature (below 400 °C). The electrolytes include direct proton conductors as well as indirect proton conductors like aqueous hydroxide. Research also encompasses electrocatalysis and development of complete cells around proton conducting electrolytes.. We synthesize polymers and manufacture and characterize proton conducting membranes. Special attention is devoted to high temperature membranes (polybenzimidazole, PBI) with chemical stability in acid as well as in base. Such polymers have been successfully applied in high-temperature PEM fuel cells, a research field in which we are pioneers. Lately, similar membranes have been successfully applied in alkaline electrolysis cells. Solid or liquid inorganic proton conductors are also studied for electrolysis above 200 °C. Within electrocatalysis our research focus is ...
The strategy applied in the structure refinement of accurate single-crystal neutron diffraction data for pseudo-centrosymmetric proton conducting systems can often be decisive. The application of a combination of judicious symmetry constraints and symmet. ...
In all cross-shore gradient-dependent mortality models the mortality function M was determined either by the cross-shore location of the particle (ADG), or by the cross-shore location of the particle and scaled solar insolation (ADGI). The cross-shore dependence of M was similar to the horizontal diffusion function used in all models (Eq. (1)): equation(8) ADG model:M=m1+m0-m121-tanhy-y0yscale equation(9) ADGI model:M=I(t)Imaxm1+m0-m121-tanhy-y0yscalewhere. m0 is surfzone mortality, m1 is offshore mortality, y0 is the offshore edge of the surfzone, and yscale determines the cross-shore scale of the surfzone/offshore transition. Values for y0 and yscale BGJ398 mouse were 50 m and 5 m, respectively, the same values used to parameterize diffusivity (Eq. (1)). Note that in the ADG and ADGI models, mortality is not an intrinsic property of a given particle (as in the ADS and ADSI models). Instead, particles move through stationary cross-shore mortality gradients and take on different mortality rates ...
Proposes the law of motive force as a fundamental law of nature and establishes its relation to other laws and principles in thermodynamics With the aid
BAM15, ST056388, mitochondrial protonophore uncoupler that does not depolarize the plasma membrane IDNUMBER ST056388 Other identifiers: SBB001916, ST4027337, T4021910, TBB011486, T3149443, ST236891 Formula: C16H10F2N6O MW: 340. 29 NAME: (2-fluorophenyl)amine SMILES: c12c(nc(c(n1)Nc1c(F)cccc1)Nc1c(F)cccc1)non2 InChI=1S/C16H10F2N6O/c17-9-5-1-3-7-11(9)19-13-14(20-12-8-4-2-6-10(12)18)22-16-15(21-13)23-25-24-16/h1-8H,(H,19,21,23)(H,20,22,24) InChIKey=OEGJBRZAJRPPHL-UHFFFAOYSA-N MDL: MFCD00373912 Contact us to order....
Anion effects on valinomycin-cation complexes". Journal of the American Chemical Society. 104 (15): 4085-4091. doi:10.1021/ ... An example of a carrier ionophore is valinomycin, a molecule that transports a single potassium cation. Carrier ionophores may ... Thompson, Michael; Krull, U.J. (September 1982). "The electroanalytical response of the bilayer lipid membrane to valinomycin: ... Steinrauf, L. K.; Hamilton, J. A.; Sabesan, M. N. (1982). "Crystal structure of valinomycin-sodium picrate. ...
... is a cyclic dodecadepsipeptide resembling valinomycin; it contains three repeats of four amino acids: D-Oxy-Leu-D-Ala ...
... also produces the ionophore valinomycin. Streptomyces microflavus is also known to cause potato common ...
... can be used for valinomycin biosynthesis. Braña, AF; Fiedler, HP; Nava, H; González, V; Sarmiento- ...
Transport Mediated by Valinomycin-like Carriers". Chem. 1 (1): 127-146. doi:10.1016/j.chempr.2016.04.002. Spooner, Michael J.; ...
Other compounds containing D-amino acids are tyrocidine and valinomycin. These compounds disrupt bacterial cell walls, ...
For example, a K+ sensor was produced by incorporating valinomycin into a thin membrane. In 1953, Watson and Crick announced ...
Rose L, Jenkins AT (2006). "The effect of the ionophore valinomycin on biomimetic solid supported lipid DPPTE/EPC membranes". ...
... a potassium ion-selective membrane electrode utilizes the naturally occurring macrocyclic antibiotic valinomycin. In this case ...
For example, an electrode based on Valinomycin may be used for the determination of potassium ion concentration. Fluoride ... based on valinomycin as an ion-exchange agent. Enzyme electrodes are not true ion-selective electrodes, but are usually ...
Applying ionophores like valinomycin can create electrochemical gradients comparable to the gradients inside living cells. ...
This ion selectivity is seen in other macrocyclic ligands, such as the cyclic ionophore valinomycin, which is also an ... "Freezing and Melting of Lipid Bilayers and the Mode of Action of Nonactin, Valinomycin, and Gramicidin." Freezing and Melting ... of Lipid Bilayers and the Mode of Action of Nonactin, Valinomycin, and Gramicidin. Sigma-Aldrich, n.d. Web.] [Total synthesis ...
Ionophores such as valinomycin also display a marked preference for the potassium cation over other cations. Crown ethers have ...
... effects on energized ion fluxes in the presence of valinomycin". Biochemical Pharmacology. 24 (18): 1701-1705. doi:10.1016/0006 ...
M. B. Sankaram, K. R. K. Easwaran (August 1982). "CD and nmr studies on the interaction of lithium ion with valinomycin and ...
Effects on Energized Ion Fluxes in the Presence of Valinomycin". Biochemical Pharmacology. 24 (18): 1701-5. doi:10.1016/0006- ...
... effects on energized ion fluxes in the presence of valinomycin". Biochemical Pharmacology. 24 (18): 1701-1705. doi:10.1016/0006 ...
"Action of propranolol on mitochondrial functions-effects on energized ion fluxes in the presence of valinomycin". Biochemical ...
Third, Mg2+ efflux was observed via Mrs2p upon the artificial depolarisation of the mitochondrial membrane by valinomycin. ...
... potassium selective electrodes are available that make use of the naturally occurring macrocyclic antibiotic valinomycin. An ...
Synthesis of analogs of valinomycin with modified side chains and different contents of amide and ester groups, Chem Nat Compd ... Relation between structure and properties of cyclodepsipep-tides of valinomycin series, Russ Chem Bull 23, 2225-2232 (1974). ... Synthesis of new analogs of valinomycin and their properties, I. Chem Nat Compd 10, 238-243 (1974). https://doi.org/10.1007/ ... and antimicrobial activity in a series of analogs of valinomycin, Chem Nat Compd 9, 229-234 (1973). https://doi.org/10.1007/ ...
These electrodes are typical ion exchange resin membrane electrodes, using valinomycin, a potassium ionophore, as the ion ...
It has also been noted that glycine transport is inhibited by a protonophore, FCCP, or valinomycin plus nigericin, indicating ...
Valinomycin, Nonactin, Ionomycin Special antibiotics and molecular biology reagents. Anisomycin, Thiolutin, Wortmannin, K252a, ...
Dactinomycin Daptomycin Gramicidin S Hymenistatin Microcystins Nisin Nodularin Octreotide Polymyxin B Pristinamycin Valinomycin ...
... similar to valinomycin produced by Streptomyces griseus) produced by nonribosomal peptide synthesis. Cereulide is believed to ...
Family 2.B.1 The Valinomycin Carrier Family 2.B.2 The Monensin Family 2.B.3 The Nigericin Family 2.B.4 The Macrotetrolide ...
Tetraphenylphosphonium chloride Valinomycin Arsenate Uncoupling protein Not to be confused with the recreation drug, ...
C5H4N4O3 Uridine Valine Valinomycin Vanabins Vasopressin Verruculogen Vitamins (in general) Vitamin A (retinol) Vitamin B () ...
... amine Valinomycin Vinyl acetate monomer Warfarin Warfarin sodium Xylylene dichloride Zinc phosphide List of highly toxic gases ...
The potassium electrode consists of valinomycin membrane. The voltage (potential) change that takes place within the membrane ...
Previous studies with protease deficient mice and additional studies with valinomycin (DOC 21 kb). ...
Ligand 8 a, fixed in the 1,3-alternate conformation, is more selective than valinomycin and shows the highest K+/Na+ ... Ligand 8 a, fixed in the 1,3-alternate conformation, is more selective than valinomycin and shows the highest K+/Na+ ... 1,3-Alternate calix[4]arenecrown-5 conformers: new synthetic ionophores with better K+/Na+ selectivity than valinomycin. ... Results were compared to those obtained with with the natural antibiotic valinomycin 1. All ligands showed high selectivity for ...
... valinomycin and monensin, that facilitate potassium transport by different mechanisms. Valinomycin is an electrogenic ... In all cases, ~100% chloride efflux was achieved in the presence of valinomycin. Receptors 1-5 displayed a small degree (,20%) ... Nonprotonophoric Electrogenic Cl− Transport Mediated by Valinomycin-like Carriers. Chem 2016, 1, 127-146. [Google Scholar] [ ... KCl efflux monitored by a chloride ISE (navy) induced by valinomycin (Vln, blue) facilitated electrogenic K+ transport coupled ...
5-FU, 5-fluorouracil; CTR, control; MET, metformin; NAC, N-acetyl cysteine; OXAL, oxaliplatin; VAL, valinomycin. At least three ... Treatment with valinomycin (25 µM; Thermo Fisher Scientific, Inc.) for 2 h at 37°C was used as a positive control for ...
Valinomycin and nigericin were obtained from Tocris Bioscience (Bristol, UK). Standard salts used for solutions were obtained ... and the K+-selective ionophore valinomycin, to have control of Ψly simply by changing the K+ concentration in the extracellular ...
concentration of valinomycin. Nearly identical curves were obtained with both analysis methods, and in both cases the IC50 ... PC-12 cells were treated with valinomycin and assayed for mitochondrial activity using MitoTracker™ Deep Red FM (MTDR) dye. ... Left, untreated cells; right, cells treated with 1 µM valinomycin. For each individual cell identified, the intensity of ...
1080) and valinomycin (VA; Cat. # 3373) were ordered from Tocris Bioscience. PMID: 27183222 ...
... human leukaemic K562 cells were monitored after exposure to staurosporine and valinomycin. The DEP response curves showed the ...
Naumann, R.; Walz, D.; Schiller, S. M.; Knoll, W.: Kinetics of valinomycin-mediated K+ ion transport through tethered bilayer ...
The membrane potential (Ψ) clamped by valinomycin (Vln), a K+ ionophore, in the presence of a predefined K+ gradient could be ...
k) Uncouplers of the proton motive force such as FCCP, CCCP, DIDS, valinomycin, nigericin indirectly inhibit VGLUT activity by ...
Some of them are superior to naturally existing neutral carriers such as valinomycin, which is highly selective for potassium ...
Cells and vesicles artificially energized with valinomycin transported glucose or 2-deoxyglucose at rates greater than those of ... Cells and vesicles artificially energized with valinomycin transported glucose or 2-deoxyglucose at rates greater than those of ...
Valinomycin - Preferred Concept UI. M0022498. Scope note. A cyclododecadepsipeptide ionophore antibiotic produced by ... From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies ... From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies ...
Synonyms:. Chemical names:. IUPAC:. (3S,6R,9S,12R,15S,18R)-4,10,16-trimethyl-3,6,9,12,15,18-hexa(propan-2-yl)-1,7,13-trioxa-4,10,16-triazacyclooctadecane-2,5,8,11,14,17-hexone. IUPAC Condensed name, as an ...
... valinomycin, and nonactin which interact primarily with lipid head groups and are readily incorporated into the tetraether ...
Tl-205 Nuclear Magnetic-Resonance Investigation of Thallium(i)-Valinomycin Complex. by Briggs, Richard W.; Hinton, James F. ... Tl-205 Nuclear Magnetic-Resonance Investigation of Thallium(i)-Valinomycin Complex. ...
scientific article published on April 1, 1975
Valinomycin. 86. Nonribosomal peptide biosynthesis. Nonribosomal peptide biosynthesis. NRPS. Salinomycin. 14. Nonribosomal ... Jeon C.-W., Kim D.-R., Kwak Y.-S.. 2019;Valinomycin, produced by Streptomyces sp. S8, a key antifungal metabolite in large ... Louis, MO, USA), sallinomycin (≥98%), bafillomycin A (≥90%), and valinomycin (≥99%) were tested for antibacterial effects with ... valinomycin, and bafilomycin were tested for their antibacterial ability with a plate assay. Only salinomycin showed ...
Valinomycin Valproic Acid Valsalva Maneuver Value of Life Value of Reference for Portions ...
Hilgemann, D. W., Lin, M. J., Fine, M., Frazier, G. & Wang, H. R., 2013, Sodium Calcium Exchange: A Growing Spectrum of Pathophysiological Implications: Proceedings of the 6th International Conference on Sodium Calcium Exchange. Springer Science and Business Media, LLC, p. 345-352 8 p. (Advances in Experimental Medicine and Biology; vol. 961).. Research output: Chapter in Book/Report/Conference proceeding › Conference contribution ...
cycloheximidr, 1,-amino acids, 1)-amino acids, valinomycin, CCCP, PercollTM, I,-proline agarose, L-argir~ine agarose, n-octyl-p ...
folic acid, beta-carotene, cytochrome c, valinomycin and gramicidin has been carried out. The absorption coefficient is related ...
Kaplan, J. H.; Passow, H.: Effects of phlorizin on net chloride movements across the valinomycin-treated erythrocyte membrane. ... Kaplan, J. H.; Passow, H.: Proceedings: tasymmetric effects of phlorizin on valinomycin-mediated ion movements across the human ...
... calibrated as a function of transmembrane voltage by generating a potassium diffusion potential in the presence of valinomycin ... calibrated as a function of transmembrane voltage by generating a potassium diffusion potential in the presence of valinomycin ...
Zebrafish Valinomycin CASRN 2001-95-8 (29 kB) * Zebrafish Valproic acid sodium salt CASRN 1069-66-5 (27 kB) ...
75351); 160?M (160?MC675?nM) valinomycin (Sigma kitty zero. V3639); and 160?M (160?MC675?nM) rapamycin (Sigma kitty zero. R8781 ...
  • The anion response of the potassium / valinomycin electrode with the variation of the concentration of valinomycin, type of plasticizer and PVC have been clarified. (ncl.ac.uk)
  • The anion response of the membrane is shown to be influenced by the nature of membrane and concentration of valinomycin. (ncl.ac.uk)
  • Some of them are superior to naturally existing neutral carriers such as valinomycin, which is highly selective for potassium ions. (dojindo.com)
  • From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies. (bvsalud.org)
  • The fluorescence change can be calibrated as a function of transmembrane voltage by generating a potassium diffusion potential in the presence of valinomycin. (uni-konstanz.de)
  • General Information: Produces the antibiotic Valinomycin that increases the transport of potassium across cell membranes. (up.ac.za)
  • In this work, optimization of the performance of potassium / PVC electrodes based on valinomycin, with respect to the composition of the membrane, i. e. the ratio of valinomycin to plasticizer, and the type of PVC matrix has been investigated, in an attempt to reduce the cost of the commercially available electrode. (ncl.ac.uk)
  • SOLVED:Valinomycin is an antibiotic. (numerade.com)
  • Results were compared to those obtained with with the natural antibiotic valinomycin 1. (unipr.it)
  • Cells and vesicles artificially energized with valinomycin transported glucose or 2-deoxyglucose at rates greater than those of de-energized cells, indicating that a membrane potential could drive uptake by the low-affinity system. (unl.edu)
  • Effects of phlorizin on net chloride movements across the valinomycin-treated erythrocyte membrane. (mpg.de)
  • Proceedings: tasymmetric effects of phlorizin on valinomycin-mediated ion movements across the human erythrocyte membrane. (mpg.de)
  • A valinomycin/K+-induced membrane potential (PD, inside negative) doubled 45Ca uptake at pH 7.0 above that in the absence of a PD (p (unf.edu)
  • The method permitted an estimate of the valinomycin concentration after valinomycin was leached from a membrane. (memphis.edu)
  • The addition of 1 ?M 3,5-di-tert-butyl-4-hydroxybenzylidene malononitrile (SF6847), a proton conductor, and 5 ?M nigericin in the presence of KCl, which dissipates the pH gradient, both strongly inhibited the uptake, whereas 1 ?M valinomycin in the presence of 65 mM KCl, which causes membrane depolarization, did not have much effect (Fig. 2E). (skpfotbal.cz)
  • Kinetics of valinomycin-mediated K + ion transport through tethered bilayer lipid membranes. (mpg.de)
  • The membranes contained between 0.5 and 16 mmol/kg valinomycin. (memphis.edu)
  • The chronoamperometric technique was used to estimate the valinomycin concentration in freshly prepared membranes and after extraction of some of the ionophore from the membranes using dioctyl sebacate. (memphis.edu)
  • Ligand 8 a, fixed in the 1,3-alternate conformation, is more selective than valinomycin and shows the highest K+/Na+ selectivity known so far. (unipr.it)
  • Valinomycin is an antibiotic which acts as a potassium (K+) ionophore. (agscientific.com)
  • [ 9 ] Valinomycin, a potassium ionophore, exhibited activity against La Crosse virus in multiple cell types in a dose-dependent manner, suggesting a potential therapeutic target to disrupt virus replication. (medscape.com)
  • From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies. (nih.gov)
  • Limiting fluorescence is determined by addition of the specific K + ionophore valinomycin. (amazing4you.de)
  • The characteristic features of the chronoamperometric curves (initial current, slope, break time) of valinomycin-based, potassium-selective membranes loaded with potassium tetrakis(4-chlorophenyl)borate are correlated with the mobile-site and free ionophore concentration in the membrane. (memphis.edu)
  • Ion channels made by microbes as part of their competitive arsenal can be stunningly simple and highly effective: valinomycin, secreted by Streptomyces , is a circular ring of only 12 amino acids. (madamescientist.com)
  • Given that depolarizing the plasma membrane potential in high K + buffer results in lowering the uptake of [ 99m Tc]MIBI and that alteration of the mitochondrial membrane potential with valinomycin or nigericin induces, respectively, a significant decrease or increase of [ 99m Tc]MIBI uptake, we propose that the plasma and mitochondrial membrane potentials play a major role in the uptake. (aacrjournals.org)
  • 3) Since these discrepancies between internal acidification and phosphorylation are found in the presence of saturating amounts of valinomycin and KCl, it seems that photophosphorylation can occur when there are no proton concentration gradients and no electrical potential differences across the membranes which separate the medium from the greater part of the internal aqueous phase. (illinois.edu)
  • Differences in sensitivity to valinomycin and nonactin of various photophosphorylating and photoreducing systems of Rhodospirillum rubrum chromatpohores. (wikidata.org)
  • Freezing and melting of lipid bilayers and the mode of action of nonactin, valinomycin and gramicidin. (microbiologyresearch.org)
  • Valinomycin also inhibits hyphal growth in other dimorphic fungi, Candida tropicalis and Aureobasidium pullulan. (agscientific.com)
  • Except for the inhibition of valinomycin-induced swelling, the following order of potency for all assays was obtained: chlordecone alcohol greater than or equal to chlordecone greater than monohydrochlordecone much greater than dihydrochlordecone. (nih.gov)
  • Measurements in the presence of valinomycin and an outwardly directed K+ gradient strongly suggest that H(+)-stimulated uptake at both concentrations is electrogenic, and competitive inhibition of Gly-Pro transport was demonstrated for the dipeptides Gly-Gly and Gly-Sar. (semanticscholar.org)
  • Valinomycin induced stimulation of mitochondrial energy dependent reversible swelling, supported by succinate oxidation, cytochrome c (cyto-c) and sulfite oxidase (Sox) (both are present in the mitochondrial intermembrane space (MIS)) are released outside. (agscientific.com)
  • Incorporation of surface plasmon resonance with novel valinomycin doped chitosan-graphene oxide thin film for sensing potassium ion. (americanelements.com)
  • In somewhat swollen chloroplasts, the combined buffering by the tris(hydroxymethyl)aminomethane and orthophosphate inside would delay acidification of the inside by 1500 ms but, even in the presence of valinomycin and KCl, the total delay in the initiation of phosphorylation is then only 65 ms. Similar discrpancies occur with all of the other buffers mentioned. (illinois.edu)
  • Coupling between sodium and proton movements in dog red blood cells was investigated directly using the fluorescent probe 3,3'- dipropylthiadicarbocyanine (diSC35) and indirectly by measurement of potassium movements through valinomycin channels. (cdc.gov)
  • In powder form, it is available at western chemical suppliers but expensive http://www.sigmaaldrich.com/catalog/search?term=3546-41-6&interface=CAS%20No.&N=0&mode=partialmax&lang=en®ion=NL&focus=product Alternatively, it is available at Chinese suppliers at a cost of about 3o0USD for 10g of substance which should be enough for applications other than oral administrations. (cancertreatmentsresearch.com)
  • 2) Photophosphorylation begins abruptly at full steady-state efficiency and full steady-state rate as soon as the illumination time exceeds about 5 ms when permeant ions are absent or as soon as the time exceeds about 50 ms if valinomycin and KCl are present. (illinois.edu)
  • Our studies with a triple mutant P-gp in a cys-less background demonstrate that when the primary binding site for cyclosporine A, tariquidar or valinomycin is disabled by mutagenesis, these drugs bind to alternate sites, which are capable of transport. (nih.gov)
  • Valinomycin is potent agent against severe acute respiratory-syndrome coronavirus (SARS-CoV) in infected Vero E6 cells. (agscientific.com)
  • Furthermore, the association of HBV Pol-p11 with PML was increased by exposure of cells to EGTA and inhibited by valinomycin. (elsevier.com)