Cations. Medical search

Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.

Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.

Positively charged atoms, radicals or group of atoms with a valence of plus 1, which travel to the cathode or negative pole during electrolysis.

A family of proteins involved in the transport of organic cations. They play an important role in the elimination of a variety of endogenous substances, xenobiotics, and their metabolites from the body.

An organic cation transporter found in kidney. It is localized to the basal lateral membrane and is likely to be involved in the renal secretion of organic cations.

A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.

A subgroup of TRP cation channels named after melastatin protein. They have the TRP domain but lack ANKYRIN repeats. Enzyme domains in the C-terminus leads to them being called chanzymes.

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.

A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.

A subgroup of TRP cation channels that contain 3-4 ANKYRIN REPEAT DOMAINS and a conserved C-terminal domain. Members are highly expressed in the CENTRAL NERVOUS SYSTEM. Selectivity for calcium over sodium ranges from 0.5 to 10.

Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.

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 trace element with atomic symbol Mn, atomic number 25, and atomic weight 54.94. It is concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone, influences the synthesis of mucopolysaccharides, stimulates hepatic synthesis of cholesterol and fatty acids, and is a cofactor in many enzymes, including arginase and alkaline phosphatase in the liver. (From AMA Drug Evaluations Annual 1992, p2035)

Membrane proteins whose primary function is to facilitate the transport of positively charged molecules (cations) across a biological membrane.

The rate dynamics in chemical or physical systems.

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)

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).

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 element of the alkaline earth family of metals. It has the atomic symbol Sr, atomic number 38, and atomic weight 87.62.

An element in the alkali metals family. It has the atomic symbol Li, atomic number 3, and atomic weight [6.938; 6.997]. Salts of lithium are used in treating BIPOLAR DISORDER.

A subgroup of TRP cation channels named after vanilloid receptor. They are very sensitive to TEMPERATURE and hot spicy food and CAPSAICIN. They have the TRP domain and ANKYRIN repeats. Selectivity for CALCIUM over SODIUM ranges from 3 to 100 fold.

High molecular weight insoluble polymers which contain functional anionic groups that are capable of undergoing exchange reactions with cations.

A member of the alkali metals. It has an atomic symbol Cs, atomic number 50, and atomic weight 132.91. Cesium has many industrial applications, including the construction of atomic clocks based on its atomic vibrational frequency.

Metals that constitute group 1(formerly group Ia) of the periodic table. They are the most strongly electropositive of the metals. Note that HYDROGEN is not considered an alkali metal even though it falls under the group 1 heading in the periodic table.

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.

A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.

A subgroup of cyclic nucleotide-regulated ION CHANNELS within the superfamily of pore-loop cation channels. They are expressed in OLFACTORY NERVE cilia and in PHOTORECEPTOR CELLS and some PLANTS.

An element of the alkaline earth group of metals. It has an atomic symbol Ba, atomic number 56, and atomic weight 138. All of its acid-soluble salts are poisonous.

An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.

The opening and closing of ion channels due to a stimulus. The stimulus can be a change in membrane potential (voltage-gated), drugs or chemical transmitters (ligand-gated), or a mechanical deformation. Gating is thought to involve conformational changes of the ion channel which alters selective permeability.

An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.

Derivatives of ammonium compounds, NH4+ Y-, in which all four of the hydrogens bonded to nitrogen have been replaced with hydrocarbyl groups. These are distinguished from IMINES which are RN=CR2.

A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.

The ability of a substrate to allow the passage of ELECTRONS.

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.

An anthranilic acid derivative with analgesic, anti-inflammatory, and antipyretic properties. It is used in musculoskeletal and joint disorders and administered by mouth and topically. (From Martindale, The Extra Pharmacopoeia, 30th ed, p16)

Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)

Voltage-dependent cell membrane glycoproteins selectively permeable to calcium ions. They are categorized as L-, T-, N-, P-, Q-, and R-types based on the activation and inactivation kinetics, ion specificity, and sensitivity to drugs and toxins. The L- and T-types are present throughout the cardiovascular and central nervous systems and the N-, P-, Q-, & R-types are located in neuronal tissue.

The parts of a macromolecule that directly participate in its specific combination with another molecule.

Lanthanum. The prototypical element in the rare earth family of metals. It has the atomic symbol La, atomic number 57, and atomic weight 138.91. Lanthanide ion is used in experimental biology as a calcium antagonist; lanthanum oxide improves the optical properties of glass.

A trace element that is a component of vitamin B12. It has the atomic symbol Co, atomic number 27, and atomic weight 58.93. It is used in nuclear weapons, alloys, and pigments. Deficiency in animals leads to anemia; its excess in humans can lead to erythrocytosis.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.

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.

The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.

A potassium-selective ion channel blocker. (From J Gen Phys 1994;104(1):173-90)

A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.

A group of membrane transport proteins that transport biogenic amine derivatives of catechol across the PLASMA MEMBRANE. Catecholamine plasma membrane transporter proteins regulate neural transmission as well as catecholamine metabolism and recycling.

The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.

The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.

The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.

The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.

A trace element with the atomic symbol Ni, atomic number 28, and atomic weight 58.69. It is a cofactor of the enzyme UREASE.

Substances produced from the reaction between acids and bases; compounds consisting of a metal (positive) and nonmetal (negative) radical. (Grant & Hackh's Chemical Dictionary, 5th ed)

Gadolinium. An element of the rare earth family of metals. It has the atomic symbol Gd, atomic number 64, and atomic weight 157.25. Its oxide is used in the control rods of some nuclear reactors.

The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.

Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.

A subgroup of TRP cation channels that are widely expressed in various cell types. Defects are associated with POLYCYSTIC KIDNEY DISEASES.

Membrane transporters that co-transport two or more dissimilar molecules in the opposite direction across a membrane. Usually the transport of one ion or molecule is against its electrochemical gradient and is "powered" by the movement of another ion or molecule with its electrochemical gradient.

A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.

An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.

A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.

An element with atomic symbol Cd, atomic number 48, and atomic weight 114. It is a metal and ingestion will lead to CADMIUM POISONING.

A group of elements that include SCANDIUM; YTTRIUM; and the LANTHANOID SERIES ELEMENTS. Historically, the rare earth metals got their name from the fact that they were never found in their pure elemental form, but as an oxide. In addition they were very difficult to purify. They are not truly rare and comprise about 25% of the metals in the earth's crust.

Metals that constitute the group 2 (formerly group IIa) of the periodic table.

Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.

A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.

A ubiquitous sodium salt that is commonly used to season food.

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 heavy, bluish white metal, atomic number 81, atomic weight [204.382; 204.385], symbol Tl.

Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).

A salt used to replenish calcium levels, as an acid-producing diuretic, and as an antidote for magnesium poisoning.

An organic amine proton acceptor. It is used in the synthesis of surface-active agents and pharmaceuticals; as an emulsifying agent for cosmetic creams and lotions, mineral oil and paraffin wax emulsions, as a biological buffer, and used as an alkalizer. (From Merck, 11th ed; Martindale, The Extra Pharmacopoeia, 30th ed, p1424)

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.

Established cell cultures that have the potential to propagate indefinitely.

Chemicals that bind to and remove ions from solutions. Many chelating agents function through the formation of COORDINATION COMPLEXES with METALS.

Reversible chemical reaction between a solid, often one of the ION EXCHANGE RESINS, and a fluid whereby ions may be exchanged from one substance to another. This technique is used in water purification, in research, and in industry.

The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.

A broad group of eukaryotic six-transmembrane cation channels that are classified by sequence homology because their functional involvement with SENSATION is varied. They have only weak voltage sensitivity and ion selectivity. They are named after a DROSOPHILA mutant that displayed transient receptor potentials in response to light. A 25-amino-acid motif containing a TRP box (EWKFAR) just C-terminal to S6 is found in TRPC, TRPV and TRPM subgroups. ANKYRIN repeats are found in TRPC, TRPV & TRPN subgroups. Some are functionally associated with TYROSINE KINASE or TYPE C PHOSPHOLIPASES.

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.

The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.

An active neurotoxic metabolite of 1-METHYL-4-PHENYL-1,2,3,6-TETRAHYDROPYRIDINE. The compound reduces dopamine levels, inhibits the biosynthesis of catecholamines, depletes cardiac norepinephrine and inactivates tyrosine hydroxylase. These and other toxic effects lead to cessation of oxidative phosphorylation, ATP depletion, and cell death. The compound, which is related to PARAQUAT, has also been used as an herbicide.

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.

Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.

The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).

Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.

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.

Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.

Transport proteins that carry specific substances in the blood or across cell membranes.

A pyrazine compound inhibiting SODIUM reabsorption through SODIUM CHANNELS in renal EPITHELIAL CELLS. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with DIURETICS to spare POTASSIUM loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)

A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)

A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.

The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.

The relationship between the dose of an administered drug and the response of the organism to the drug.

Stable cesium atoms that have the same atomic number as the element cesium, but differ in atomic weight. Cs-133 is a naturally occurring isotope.

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+

The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.

Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.

Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.

Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.

Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.

Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.

A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A subgroup of cyclic nucleotide-regulated ION CHANNELS of the superfamily of pore-loop cation channels that are opened by hyperpolarization rather than depolarization. The ion conducting pore passes SODIUM, CALCIUM, and POTASSIUM cations with a preference for potassium.

Proteins prepared by recombinant DNA technology.

Ion channels that specifically allow the passage of SODIUM ions. A variety of specific sodium channel subtypes are involved in serving specialized functions such as neuronal signaling, CARDIAC MUSCLE contraction, and KIDNEY function.

A polyamine formed from putrescine. It is found in almost all tissues in association with nucleic acids. It is found as a cation at all pH values, and is thought to help stabilize some membranes and nucleic acid structures. It is a precursor of spermine.

The accumulation of an electric charge on a object

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.

A class of sodium-independent nucleoside transporters that mediate the facilitative transport of NUCLEOSIDES.

Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.

Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.

Measurement of the intensity and quality of fluorescence.

A biogenic polyamine formed from spermidine. It is found in a wide variety of organisms and tissues and is an essential growth factor in some bacteria. It is found as a polycation at all pH values. Spermine is associated with nucleic acids, particularly in viruses, and is thought to stabilize the helical structure.

Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.

A basic constituent of lecithin that is found in many plants and animal organs. It is important as a precursor of acetylcholine, as a methyl donor in various metabolic processes, and in lipid metabolism.

The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.

Organic compounds that contain phosphorus as an integral part of the molecule. Included under this heading is broad array of synthetic compounds that are used as PESTICIDES and DRUGS.

The physical characteristics and processes of biological systems.

The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.

An ionophorous, polyether antibiotic from Streptomyces chartreusensis. It binds and transports CALCIUM and other divalent cations across membranes and uncouples oxidative phosphorylation while inhibiting ATPase of rat liver mitochondria. The substance is used mostly as a biochemical tool to study the role of divalent cations in various biological systems.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

A class of drugs that act by selective inhibition of calcium influx through cellular membranes.

The sum of the weight of all the atoms in a molecule.

Cationic ionophore antibiotic obtained from Streptomyces lasaliensis that, among other effects, dissociates the calcium fluxes in muscle fibers. It is used as a coccidiostat, especially in poultry.

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.

Elements of limited time intervals, contributing to particular results or situations.

Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.

A purinergic P2X neurotransmitter receptor that plays a role in pain sensation signaling and regulation of inflammatory processes.

The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.

A colloidal, hydrated aluminum silicate that swells 12 times its dry size when added to water.

Inorganic or organic oxy acids of sulfur which contain the RSO2(OH) radical.

1-Deoxy-1-(methylamino)-D-glucitol. A derivative of sorbitol in which the hydroxyl group in position 1 is replaced by a methylamino group. Often used in conjunction with iodinated organic compounds as contrast medium.

Stable potassium atoms that have the same atomic number as the element potassium, but differ in atomic weight. K-41 is a stable potassium isotope.

Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).

The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Stable sodium atoms that have the same atomic number as the element sodium, but differ in atomic weight. Na-23 is a stable sodium isotope.

Agents that affect ION PUMPS; ION CHANNELS; ABC TRANSPORTERS; and other MEMBRANE TRANSPORT PROTEINS.

Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.

Membrane proteins that allow the exchange of hydrogen ions for potassium ions across the cellular membrane. The action of these antiporters influences intracellular pH and potassium ion homeostasis.

High molecular weight, insoluble polymers which contain functional groups that are capable of undergoing exchange reactions (ION EXCHANGE) with either cations or anions.

A chemical system that functions to control the levels of specific ions in solution. When the level of hydrogen ion in solution is controlled the system is called a pH buffer.

An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.

The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.

A polyether antibiotic which affects ion transport and ATPase activity in mitochondria. It is produced by Streptomyces hygroscopicus. (From Merck Index, 11th ed)

Inorganic salts of phosphoric acid.

A class of cell surface receptors for PURINES that prefer ATP or ADP over ADENOSINE. P2 purinergic receptors are widespread in the periphery and in the central and peripheral nervous system.

A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).

Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.

The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.

Salts of hydrobromic acid, HBr, with the bromine atom in the 1- oxidation state. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.

A disaccharide consisting of one galactose and one glucose moiety in an alpha (1-6) glycosidic linkage.

The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.

Hemolytic anemia due to various intrinsic defects of the erythrocyte.

Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.

The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.

An inorganic dye used in microscopy for differential staining and as a diagnostic reagent. In research this compound is used to study changes in cytoplasmic concentrations of calcium. Ruthenium red inhibits calcium transport through membrane channels.

A widely distributed purinergic P2X receptor subtype that plays a role in pain sensation. P2X4 receptors found on MICROGLIA cells may also play a role in the mediation of allodynia-related NEUROPATHIC PAIN.

Contractile tissue that produces movement in animals.

The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.

A silver metallic element that exists as a liquid at room temperature. It has the atomic symbol Hg (from hydrargyrum, liquid silver), atomic number 80, and atomic weight 200.59. Mercury is used in many industrial applications and its salts have been employed therapeutically as purgatives, antisyphilitics, disinfectants, and astringents. It can be absorbed through the skin and mucous membranes which leads to MERCURY POISONING. Because of its toxicity, the clinical use of mercury and mercurials is diminishing.

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.

A fluorescent calcium chelating agent which is used to study intracellular calcium in tissues.

Proteins found in any species of bacterium.

A family of proton-gated sodium channels that are primarily expressed in neuronal tissue. They are AMILORIDE-sensitive and are implicated in the signaling of a variety of neurological stimuli, most notably that of pain in response to acidic conditions.

The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.

A general class of integral membrane proteins that transport ions across a membrane against an electrochemical gradient.

The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.

Terbium. An element of the rare earth family of metals. It has the atomic symbol Tb, atomic number 65, and atomic weight 158.92.

Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.

A constituent of STRIATED MUSCLE and LIVER. It is an amino acid derivative and an essential cofactor for fatty acid metabolism.

Artificially produced membranes, such as semipermeable membranes used in artificial kidney dialysis (RENAL DIALYSIS), monomolecular and bimolecular membranes used as models to simulate biological CELL MEMBRANES. These membranes are also used in the process of GUIDED TISSUE REGENERATION.

An inhibitor of anion conductance including band 3-mediated anion transport.

The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)

Unstable isotopes of sodium that decay or disintegrate emitting radiation. Na atoms with atomic weights 20-22 and 24-26 are radioactive sodium isotopes.

A plasma membrane exchange glycoprotein transporter that functions in intracellular pH regulation, cell volume regulation, and cellular response to many different hormones and mitogens.

Silver. An element with the atomic symbol Ag, atomic number 47, and atomic weight 107.87. It is a soft metal that is used medically in surgical instruments, dental prostheses, and alloys. Long-continued use of silver salts can lead to a form of poisoning known as ARGYRIA.

Unstable isotopes of rubidium that decay or disintegrate emitting radiation. Rb atoms with atomic weights 79-84, and 86-95 are radioactive rubidium isotopes.

Phenolic metacyclophanes derived from condensation of PHENOLS and ALDEHYDES. The name derives from the vase-like molecular structures. A bracketed [n] indicates the number of aromatic rings.

Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A sesquiterpene lactone found in roots of THAPSIA. It inhibits CA(2+)-TRANSPORTING ATPASE mediated uptake of CALCIUM into SARCOPLASMIC RETICULUM.

The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

The process of cleaving a chemical compound by the addition of a molecule of water.

Substances that dissociate into two or more ions, to some extent, in water. Solutions of electrolytes thus conduct an electric current and can be decomposed by it (ELECTROLYSIS). (Grant & Hackh's Chemical Dictionary, 5th ed)

A subclass of purinergic P2 receptors that signal by means of a ligand-gated ion channel. They are comprised of three P2X subunits which can be identical (homotrimeric form) or dissimilar (heterotrimeric form).

A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).

Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.

The characteristic three-dimensional shape of a molecule.

The contribution of adjacent subunits to the active sites of D-3-phosphoglycerate dehydrogenase. (1/3963)

D-3-Phosphoglycerate dehydrogenase (PGDH) from Escherichia coli is allosterically inhibited by L-serine, the end product of its metabolic pathway. Previous results have shown that inhibition by serine has a large effect on Vmax and only a small or negligible effect on Km. PGDH is thus classified as a V-type allosteric enzyme. In this study, the active site of PGDH has been studied by site-directed mutagenesis to assess the role of certain residues in substrate binding and catalysis. These consist of a group of cationic residues (Arg-240, Arg-60, Arg-62, Lys-39, and Lys-141') that potentially form an electrostatic environment for the binding of the negatively charged substrate, as well as the only tryptophan residue found in PGDH and which fits into a hydrophobic pocket immediately adjacent to the active site histidine residue. Interestingly, Trp-139' and Lys-141' are part of the polypeptide chain of the subunit that is adjacent to the active site. The results of mutating these residues show that Arg-240, Arg-60, Arg-62, and Lys-141' play distinct roles in the binding of the substrate to the active site. Mutants of Trp-139' show that this residue may play a role in stabilizing the catalytic center of the enzyme. Furthermore, these mutants appear to have a significant effect on the cooperativity of serine inhibition and suggest a possible role for Trp-139' in the cooperative interactions between subunits. (+info)

The stimulatory effects of Hofmeister ions on the activities of neuronal nitric-oxide synthase. Apparent substrate inhibition by l-arginine is overcome in the presence of protein-destabilizing agents. (2/3963)

A variety of monovalent anions and cations were effective in stimulating both calcium ion/calmodulin (Ca2+/CaM)-independent NADPH-cytochrome c reductase activity of, and Ca2+/CaM-dependent nitric oxide (NO.) synthesis by, neuronal nitric oxide synthase (nNOS). The efficacy of the ions in stimulating both activities could be correlated, in general, with their efficacy in precipitating or stabilizing certain proteins, an order referred to as the Hofmeister ion series. In the hemoglobin capture assay, used for measurement of NO. production, apparent substrate inhibition by L-arginine was almost completely reversed by the addition of sodium perchlorate (NaClO4), one of the more effective protein-destabilizing agents tested. Examination of this phenomenon by the assay of L-arginine conversion to L-citrulline revealed that the stimulatory effect of NaClO4 on the reaction was observed only in the presence of oxyhemoglobin or superoxide anion (generated by xanthine and xanthine oxidase), both scavengers of NO. Spectrophotometric examination of nNOS revealed that the addition of NaClO4 and a superoxide-generating system, but neither alone, prevented the increase of heme absorption at 436 nm, which has been attributed to the nitrosyl complex. The data are consistent with the release of autoinhibitory NO. coordinated to the prosthetic group of nNOS, which, in conjunction with an NO. scavenger, causes stimulation of the reaction. (+info)

Screening for mutations of the cationic trypsinogen gene: are they of relevance in chronic alcoholic pancreatitis? (3/3963)

BACKGROUND: In hereditary pancreatitis mutations of exons 2 (N21I) and 3 (R117H) of the cationic trypsinogen gene have been described. AIMS: To investigate whether the same mutations can also be found in patients with chronic alcoholic pancreatitis. METHODS: Leucocyte DNA was prepared from 23 patients with chronic alcoholic pancreatitis, 21 with alcoholic liver cirrhosis, 34 individuals from seven independent families with hereditary pancreatitis, and 15 healthy controls. DNA was also obtained from pancreatic tissue (n=7) and from pancreatic juice (n=5) of patients suffering from chronic alcoholic pancreatitis. R117H was detected by restriction digestion with Afl III. N21I was identified by an allele specific polymerase chain reaction (PCR). RESULTS: R117H was detected in four families with hereditary pancreatitis. The N21I mutation was identified in three families. All mutations were confirmed by sequencing of the corresponding DNAs. In patients with chronic alcoholic pancreatitis neither the exon 2 nor exon 3 mutations were present in blood leucocytes, pancreatic juice, or pancreatic tissue. DNA of the patients with alcoholic liver cirrhosis as well as all controls was of wild type. CONCLUSIONS: The allele specific PCR may be used to screen for the N21I mutation of cationic trypsinogen. Both trypsinogen mutations were found in hereditary pancreatitis but do not seem to be major pathogenic factors in chronic alcoholic pancreatitis. (+info)

Location of a cation-binding site in the loop between helices F and G of bacteriorhodopsin as studied by 13C NMR. (4/3963)

The high-affinity cation-binding sites of bacteriorhodopsin (bR) were examined by solid-state 13C NMR of samples labeled with [3-13C]Ala and [1-13C]Val. We found that the 13C NMR spectra of two kinds of blue membranes, deionized (pH 4) and acid blue at pH 1.2, were very similar and different from that of the native purple membrane. This suggested that when the surface pH is lowered, either by removal of cations or by lowering the bulk pH, substantial change is induced in the secondary structure of the protein. Partial replacement of the bound cations with Na+, Ca2+, or Mn2+ produced additional spectral changes in the 13C NMR spectra. The following conclusions were made. First, there are high-affinity cation-binding sites in both the extracellular and the cytoplasmic regions, presumably near the surface, and one of the preferred cation-binding sites is located at the loop between the helix F and G (F-G loop) near Ala196, consistent with the 3D structure of bR from x-ray diffraction and cryoelectron microscopy. Second, the bound cations undergo rather rapid exchange (with a lifetime shorter than 3 ms) among various types of cation-binding sites. As expected from the location of one of the binding sites, cation binding induced conformational alteration of the F-G interhelical loop. (+info)

Modulation of slow inactivation in human cardiac Kv1.5 channels by extra- and intracellular permeant cations. (5/3963)

1. The properties and regulation of slow inactivation by intracellular and extracellular cations in the human heart K+ channel hKv1.5 have been investigated. Extensive NH2- and COOH-terminal deletions outside the central core of transmembrane domains did not affect the degree of inactivation. 2. The voltage dependence of steady-state inactivation curves of hKv1.5 channels was unchanged in Rb+ and Cs+, compared with K+, but biexponential inactivation over 10 s was reduced from approximately 100 % of peak current in Na+ to approximately 65 % in K+, approximately 50 % in Rb+ and approximately 30 % in Cs+. This occurred as a result of a decrease in both fast and slow components of inactivation, with little change in inactivation time constants. 3. Changes in extracellular cation species and concentration (5-300 mM) had only small effects on the rates of inactivation and recovery from inactivation (tau recovery approximately 1 s). Mutation of residues at a putative regulatory site at R487 in the outer pore mouth did not affect slow inactivation or recovery from inactivation of hKv1.5, although sensitivity to extracellular TEA was conferred. 4. Symmetrical reduction of both intra- and extracellular cation concentrations accelerated and augmented both components of inactivation of K+ (Kd = 34.7 mM) and Cs+ (Kd = 20.5 mM) currents. These effects could be quantitatively accounted for by unilateral reduction of intracellular K+ (K+i) (Kd = 43.4 mM) or Cs+i with constant 135 mM external ion concentrations. 5. We conclude that inactivation and recovery from inactivation in hKv1.5 were not typically C-type in nature. However, the ion species dependence of inactivation was still closely coupled to ion permeation through the pore. Intracellular ion modulatory actions were more potent than extracellular actions, although still of relatively low affinity. These results suggest the presence of ion binding sites capable of regulating inactivation located on both intracellular and extracellular sides of the pore selectivity filter. (+info)

Gating current studies reveal both intra- and extracellular cation modulation of K+ channel deactivation. (6/3963)

1. The presence of permeant ions can modulate the rate of gating charge return in wild-type human heart K+ (hKv1.5) channels. Here we employ gating current measurements in a non-conducting mutant, W472F, of the hKv1.5 channel to investigate how different cations can modulate charge return and whether the actions can be specifically localized at the internal as well as the external mouth of the channel pore. 2. Intracellular cations were effective at accelerating charge return in the sequence Cs+ > Rb+ > K+ > Na+ > NMG+. Extracellular cations accelerated charge return with the selectivity sequence Cs+ > Rb+ > Na+ = NMG+. 3. Intracellular and extracellular cation actions were of relatively low affinity. The Kd for preventing slowing of the time constant of the off-gating current decay (tau off) was 20.2 mM for intracellular Cs+ (Cs+i) and 358 mM for extracellular Cs+ (Cs+o). 4. Both intracellular and extracellular cations can regulate the rate of charge return during deactivation of hKv1.5, but intracellular cations are more effective. We suggest that ion crystal radius is an important determinant of this action, with larger ions preventing slowing more effectively. Important parallels exist with cation-dependent modulation of slow inactivation of ionic currents in this channel. However, further experiments are required to understand the exact relationship between acceleration of charge return and the slowing of inactivation of ionic currents by cations. (+info)

Phospholipid-subclass-specific partitioning of lipophilic ions in membrane-water systems. (7/3963)

Herein, we systematically investigate phospholipid-subclass-specific alterations in the partitioning of both cationic and anionic amphiphiles to identify the importance of ester, ether and vinyl ether linkages at the sn-1 position of phospholipids in the partitioning of charged amphiphiles. The results demonstrated that the membrane-water partition coefficient of a prototypic cationic amphiphile (i.e. 3,3'-dipropylthiadicarbocyanine iodide) was approximately 2.5 times higher in membranes comprised of plasmenylcholine in comparison with membranes comprised of either phosphatidylcholine or plasmanylcholine. In striking contrast, the membrane-water partition coefficient of a prototypic anionic amphiphile [i.e. bis-(1,3-dibutylbarbituric acid)trimethine oxonol] in membranes comprised of plasmenylcholine was approximately 2.5 times lower than that manifest in membranes comprised of phosphatidylcholine or plasmanylcholine. Utilizing theseexperimentally determined partition coefficients,the relative membrane dipole potential of membranes comprised of plasmenylcholine was calculated and found to be approximately 25 mV lower than in membranes comprised of phosphatidylcholine or plasmanylcholine. This lower membrane dipole potential in membranes comprised of plasmenylcholine is equivalent to the membrane potential induced by incorporation of approximately 25 mol% of anionic phospholipids in membranes comprised of phosphatidylcholine. Collectively, these results demonstrate that phospholipid-subclass-specific differences in the membrane dipole potential contribute to alterations in the partitioning of lipophilic ions in membrane bilayers comprised of distinct phospholipid subclasses. Moreover, they suggest that these physicochemical differences can be exploited to facilitate the targeting of charged lipophilic drugs to specific cells and subcellular membrane compartments. (+info)

Partitioning of triphenylalkylphosphonium homologues in gel bead-immobilized liposomes: chromatographic measurement of their membrane partition coefficients. (8/3963)

Unilamellar liposomes of small or large size, SUVs and LUVs, respectively, were stably immobilized in the highly hydrophilic Sepharose 4B or Sephacryl S-1000 gel beads as a membrane stationary phase for immobilized liposome chromatography (ILC). Lipophilic cations of triphenylmethylphosphonium and tetraphenylphosphonium (TPP+) have been used as probes of the membrane potential of cells. Interaction of TPP+ and triphenylalkylphosphonium homologues with the immobilized liposomal membranes was shown by their elution profiles on both zonal and frontal ILC. Retardation of the lipophilic cations on the liposome gel bed was increased as the hydrophobicity of the cations increased, indicating the partitioning of lipophilic cations into the hydrocarbon region of the membranes. The cations did not retard on the Sepharose or Sephacryl gel bed without liposomes, confirming that the cations only interact with the immobilized liposomes. Effects of the solute concentration, flow rate, and gel-matrix substance on the ILC were studied. The stationary phase volume of the liposomal membranes was calculated from the volume of a phospholipid molecule and the amount of the immobilized phospholipid, which allowed us to determine the membrane partition coefficient (KLM) for the lipophilic cations distributed between the aqueous mobile and membrane stationary phases. The values of KLM were generally increased with the hydrophobicity of the solutes increased, and were higher for the SUVs than for the LUVs. The ILC method described here can be applied to measure membrane partition coefficients for other lipophilic solutes (e.g., drugs). (+info)

C60 cations[edit]. C60 oxidizes with difficulty. Three reversible oxidation processes have been observed by using cyclic ... Redox reactions - C60 anions and cations[edit]. C60 anions[edit]. See also: Fullerides ... 7.7 Redox reactions - C60 anions and cations *7.7.1 C60 anions ...

https://en.wikipedia.org/wiki/Buckyballs

Identification of alkaline earth cations[edit]. The flame test The table below[74] presents the colours observed when the flame ... which the alkaline earth metals readily lose to form cations with charge +2, and an oxidation state of +2.[5] ...

https://en.wikipedia.org/wiki/Alkaline-earth_metal

Cation exchange[edit]. Cation exchange sorbents are derivatized with functional groups that interact and retain positively ... Strong cation exchange sorbents contain aliphatic sulfonic acid groups that are always negatively charged in aqueous solution, ... Strong cation exchange sorbents are useful because any strongly basic impurities in the sample will bind to the sorbent and ... and weak cation exchange sorbents contain aliphatic carboxylic acids, which are charged when the pH is above about 5. ...

https://en.wikipedia.org/wiki/Solid_phase_extraction

Guanidinium cation[edit]. The conjugate acid is called the guanidinium cation, (C(NH. 2)+. 3). This planar, symmetric ion ... Via the intermediacy of biguanidine, this ammonolysis step affords salts of the guanidinium cation (see below). In the second ... 1 cation in aqueous solution due to the efficient resonance stabilization of the charge and efficient solvation by water ...

https://en.wikipedia.org/wiki/Guanidine

Anion/cation analysis[edit]. See also: Qualitative inorganic analysis. Precipitate formation is useful in the detection of the ... To identify the cation, the color of the precipitate and its solubility in excess are noted. Similar processes are often used ... type of cation in a salt. To do this, an alkali first reacts with the unknown salt to produce a precipitate that is the ...

https://en.wikipedia.org/wiki/Precipitation_

Flavylium cation derivatives[edit]. Main article: Anthocyanidin. Selected anthocyanidins and their substitutions Basic ... October 2008). "Singlet oxygen quenching by anthocyanin's flavylium cations". Free Radical Research. 42 (10): 885-91. doi: ...

https://en.wikipedia.org/wiki/Anthocyanins

The phosphonium (more obscurely: phosphinium) cation describes polyatomic cations with the chemical formula PR+. 4 (R = H, ... Types of phosphonium cationsEdit. Protonated phosphinesEdit. The parent phosphonium is PH+. 4 as found in the iodide salt, ... The quaternary phosphonium cations include tetraphenylphosphonium, (C6H5)4P+ and tetramethylphosphonium P(CH. 3)+. 4. ... Quaternary phosphonium cations (PR+. 4) are produced by alkylation of organophosphines.[3] For example, the reaction of ...

https://en.m.wikipedia.org/wiki/Phosphonium_salt

... cationsEdit. The adamantane cation can be produced by reacting 1-fluoro-adamantane with SbF5 and it has high ... tert-butanol (t-BuOH) and sulfuric acid were added to generate adamantane cation; the cation was then carboxylated by carbon ... The 1-Adamantyl Cation". J. Am. Chem. Soc. 86 (19): 4195-4197. doi:10.1021/ja01073a058.. ... and related cations and dications". J. Am. Chem. Soc. 107 (9): 2764-2772. doi:10.1021/ja00295a032.. ...

https://en.m.wikipedia.org/wiki/Adamantane

Carbazole cations". Polymer. 24 (6): 733-738. doi:10.1016/0032-3861(83)90012-5. Partridge, R (1983). "Electroluminescence from ...

https://en.wikipedia.org/wiki/OLED

... silylium cations; [E(bipy)2]3+ (E = P, As, Sb, Bi) cations; cationic 4 coordinate Pv and Sbv derivatives) and transition-metal ... and borenium cations, and its application to these and various other boron compounds has been reviewed. The Gutmann-Beckett ... 3 and synthons for EI and Ev cations", Chemical Sciences, 2015, 6, 6545-6555. doi: 10.1039/C5SC02423D J.M. Bayne and D.W. ...

https://en.wikipedia.org/wiki/Gutmann–Beckett_method

"Complex Fluoro Cations. II. Tetrafluoronitrogen(V) Cation, NF4+. Synthesis and Properties of NH4+AsF6−". Inorganic Chemistry. 5 ... The hexafluorochlorine (VII) cation, CIF6+, K. O. Christe, Inorg. Nucl. Chem. Lett. 8, 751, (1972) Christe, Karl O. (1973). " ... In this context, he synthesized the bent pentazenium cation, N5+, and was the first to experimentally detect the cyclic ... cation, CIF6". Inorganic and Nuclear Chemistry Letters. 8 (8): 741-745. doi:10.1016/0020-1650(72)80129-6. Chem.usc.edu ...

https://en.wikipedia.org/wiki/Karl_O._Christe