Specificity for alkali and alkaline earth cations of synthetic and natural organic complexing agents in membranes

Simon, W.; Morf, Werner E.; Meier, P C

doi:10.1007/bfb0004366

Cited by 127 publications

(30 citation statements)

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“…It is known that valinomycin undergoes conformational changes in different solvents, so crystallization from different solvents might result in conformationally different complexes in the crystalline form. [Simon 1978] It is also highly likely that several conformationally different complexes exist in solution, if the conformational barriers amongst species are low. It has been shown that the structure of {valinomycin-K + } in the crystal and solution are almost the same.…”

Section: Pmf = V M -[(2303rt)/f] δPh Equationmentioning

confidence: 99%

Physiology of ionophore transport of potassium and sodium ions across cell membranes: valinomycin and 18-crown-6 ether

Fong¹

2016

IJCBDD

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To cite this version:Clifford Fong. Physiology of ionophore transport of potassium and sodium ions across cell membranes: valinomycin and 18-crown-6 ether. International journal of computational biology and drug design, Inderscience Enterprise, 2016, 9 (3), pp.228 -246. <10.1504/IJCBDD.2016.078284>. Int. J. Computational Biology and Drug Design, 2016 Physiology of ionophore transport of potassium and sodium ions across cell membranes: Valinomycin and 18-Crown-6 Ether Clifford W. Fong Eigenenergy, Adelaide, South Australia Email: cwfong@internode.on.net Keywords: ionophore, valinomycin, crown ether, potassium ion, sodium ion, cell membrane transport, quantum mechanical modelling AbstractThe processes involved in transport of K + and Na + by the carrier ionophores valinomycin and 18-crown-6 ether across cell membranes have been elucidated using quantum mechanical modelling:1. Formation of the {ionophore-M + } complex: desolvation (ΔG desolv ) of the central cavity of the ionophore, change in configurational energy TΔS, desolvation of the M(H 2 O) 6-7 + 2. Desolvation of the {ionophore-M + } complex prior to entering the membrane environment 3. Permeation through the lipophilic environment of the membrane, which is dependent on the lipophilicity (ΔG lipo ), dipole moment μ, and molecular volume of the {ionophore-M + } complex. 4. Release of the M + on the intracellular side, and diffusion of the free ionophore back towards the extracellular side to restart the process.Results from this study show that it is possible to design molecular structures to enhance the ability of crown ethers to selectively transport alkali metal ions across lipid membranes. Biographical notesClifford Fong, MBA PhD, heads Eigenenergy, an organisation providing consultancy services to the energy and drug industries.

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Section: Pmf = V M -[(2303rt)/f] δPh Equationmentioning

confidence: 99%

Physiology of ionophore transport of potassium and sodium ions across cell membranes: valinomycin and 18-crown-6 ether

Fong¹

2016

IJCBDD

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“…Valinomycingruppe -Valinomycin (l l, 13), Enniatin A, B und C (4,14), Makrotetrolide (15,16,17), Antamanid (18,19,20) und Beauvericin (11) -sind positiv geladen (11); monobasische Säuren der Nigericin-Gruppe -Nigericin (21,22), Monensin (21,23), Grisorixin (24,25), Dianemycin (21,26), X-206 (27), X-537A (28-31) -elektrisch neutral (l 1). Acyclische Antibiotika bauen bei der Komplexbüdung einen Pseudocyclus um das Kation (32).…”

Section: Metallkomplexe Makrocyclischer Neutraler Moleküle Derunclassified

“…Im Gegensatz zu Monensin (l 1) und Antamanid (l l, 18,19), die Natriumionen etwa 10 mal selektiver als Kaliumionen komplexieren, diskriminieren Valinomycin, Nactine, Enniatine, Beauvericin und Nigericin Natrium-gegenüber Kaliumionen (11). Nonactin, von Streptomycesgriseus produziert, ist als Träger-Antibiotikum zur Herstellung NH 4 """-selektiver Elektroden geeignet (5,10).…”

Section: Metallkomplexe Makrocyclischer Neutraler Moleküle Derunclassified

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Ammoniumselektive Disk-Elektrode mit dem Carrier-Antibiotikum Nonactin. Verfahren zur kontinuierlichen enzymatischen Elektroanalyse von Harnstoff, I. Mitteilung

Schindler¹,

Schindler²,

Aziz³

1978

Clinical Chemistry and Laboratory Medicine

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Zusammenfassung: Die Membran der beschriebenen ammoniumselektiven Disk-Elektrode besteht aus einer Polyvinylchlorid-Matrix mit der aktiven Phase Nonactin in Tris (2-ethylhexyl)-phosphat und Diphenylether als ioncnselektivem Kunststoff, der einerseits mit der Stirnfläche eines acrylglasummantelten Platin-Drahtes und andererseits mit der Meßflüssigkeit Kontakt hat, wobei sich an dieser Phasengrenze eine Potentialdifferenz ausbilden kann. Ammonium-selective disc-electrode with the carrier-antibiotic nonactin. A method for the continuous enzymatic, electrochemical determination of urea, LSummary: An ammonium-selective disc-electrode is described; the membrane consists of a polyvinylchloride-matrix with an active phase of nonactin in tris (2-ethylhexyl)phosphate and diphenyl ether as the ion-selective plastic. One side of the membrane is in contact with the solution to be measured and the other with the front surface of a platinum wire, which is enclosed in acrylic glass. This arrangement results in a very low drift potential. Einleitung

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“…These polyethers are of considerable interest because of their ability to form unusually strong complexes with alkali and alkalineearth cations, and because they enhance the transport of such metal ions through cellular membranes (Christensen, Eatough & Izatt, 1974;Simon, Morf & Meier, 1973;Morf, Ammann, Bissig, Pretsch & Simon, 1979). The ability of the polyethers to form complexes with these cations is attributed to the ion-dipole electrostatic interaction between the positive cation and the negative dipoles of the O atoms of the polyether ring.…”

Section: Introductionmentioning

confidence: 99%

Correlation of molecular conformation and thermodynamic stability of metalcation complexes of 1,4,7,10,13-pentaoxa-16-thiacyclooctadecane

Campbell¹,

Dalley²,

Izatt³

et al. 1981

Acta Crystallogr Sect B

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The results of crystal-structure analyses of 1,4,7,10,13-pentaoxa-16-thiacyclooctadecane (I) and its complexes with NaSCN, KSCN, RbSCN and AgNO3 are discussed. In all four complexes the cation coordinates to the five O atoms of the polyether sulfide (I). The sulfur-cation interaction for the complexes depends on the cation. The sulfur-cation interaction is strong and partially covalent with the Ag ÷ complex, but weak with the K ÷ and Rb ÷ complexes. In these three structures the S atom is directed into the cavity of the ligand. There is no interaction between the S and the cation in the Na ÷ complex. In both the Na÷-complexed and uncomplexed ligand, the S atom is directed away from the cavity of the ligand. The cation-oxygen ion-dipole electrostatic interaction is the main factor in the thermodynamic stability of the alkali-metal complexes, while the Ag ÷ complex is stabilized by both the cation-oxygen and cation-sulfur interactions. Correlations are made between the thermodynamic stabilities of cation complexes of 1,4,7,10,13,16-hexaoxacyclooctadecane, 1,4,7,10,13-pentaoxacyclopentadecane, 1,4,7,10,13,16-hexaoxacyclooctadecane-2,6-dione and (I), and molecular conformation determined by X-ray diffraction. These correlations provide a basis for determining the effect various ligand parameters have on the thermodynamic stability of polyether complexes.

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Specificity for alkali and alkaline earth cations of synthetic and natural organic complexing agents in membranes

Cited by 127 publications

References 86 publications

Physiology of ionophore transport of potassium and sodium ions across cell membranes: valinomycin and 18-crown-6 ether

Physiology of ionophore transport of potassium and sodium ions across cell membranes: valinomycin and 18-crown-6 ether

Ammoniumselektive Disk-Elektrode mit dem Carrier-Antibiotikum Nonactin. Verfahren zur kontinuierlichen enzymatischen Elektroanalyse von Harnstoff, I. Mitteilung

Correlation of molecular conformation and thermodynamic stability of metalcation complexes of 1,4,7,10,13-pentaoxa-16-thiacyclooctadecane

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