The title compound {systematic name: poly[[μ(7)-(2R)-2-amino-3-sulfonato-propano-ato]disodium]}, [Na(2)(C(3)H(5)NO(5)S)](n), was obtained through solvent-thermal reaction of l-cysteic acid and aqueous sodium hydroxide. The monomer consists of two Na(+) cations that are coordinated to the deprotonated amino acid. The latter acts as donor utilizing all available coordination sites, viz. the amino...

CHIEN, WAN-Ju, AND C. E. Stevens. Coupled active transport of Na and Cl across forestomach epithelium. Am. J. Physiol. 223(4) : 9971003. 1972.-Bidirectional fluxes of Na and Cl across the isolated, short-circuited bovine rumen epithelium were measured by both doubleand quadruple-isotope-labeling techniques. Both Na and Cl were actively transported in the direction of lumen to blood, but since C...

The membrane of the squid axon is considered on the basis of a pore model in which the distribution of the pore sizes strongly favors K(+) transfer when there is no potential. Electrical asymmetry causes non-penetrating ions on the membrane capacitor to exert a mechanical force on both membrane surfaces and this force results in a deformation of the membrane pore system such that it assumes a d...

With a mean precipitation rate, much lower than that of the world, Iran is among the countries that face severe water challenges. The present study has dealt with the evaluation of hydrochemistry of Faryab spring water in Hormozgan Province, Iran. Four different composite water samples have been analyzed to detect major anions, cations, total dissolved solids, electrical conductivity, pH, and s...

Over the past two decades, enormous progress has been made in designing fluorescent sensors or probes for divalent metal ions. In contrast, the development of fluorescent sensors for monovalent metal ions, such as sodium (Na(+)), has remained underdeveloped, even though Na(+) is one the most abundant metal ions in biological systems and plays a critical role in many biological processes. Here, ...

The epithelial Na+ channel (ENaC) is highly selective for Na+ and Li+ over K+ and is blocked by the diuretic amiloride. ENaC is a heterotetramer made of two alpha, one beta, and one gamma homologous subunits, each subunit comprising two transmembrane segments. Amino acid residues involved in binding of the pore blocker amiloride are located in the pre-M2 segment of beta and gamma subunits, whic...

Electrogenic binding of ions from the cytoplasmic side of the Na+,K+ ATPase has been studied by measurements of changes of the membrane capacitance and conductance triggered by a jump of pH or of the sodium ion concentration in the absence of ATP. The pH jumps were performed in experiments with membrane fragments containing purified Na+,K+ ATPase adsorbed to a bilayer lipid membrane (BLM). Prot...

Oleg V. Palashov, Dmitry S. Zheleznov,* Alexander V. Voitovich, Victor V. Zelenogorsky, Eugene E. Kamenetsky, Efim A. Khazanov, Rodica M. Martin, Katherine L. Dooley, Luke Williams, Antonio Lucianetti, Volker Quetschke, Guido Mueller, David H. Reitze, David B. Tanner, Eric Genin, Benjamin Canuel, and Julien Marque Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanova Stre...

Six-year (2005-2010) evolution of water chemistry (Cl(-), NO(3)(-), SO(4)(2-), HCO(3)(-), Na(+), K(+), Ca(2+) and Mg(2+)) and their interactions with morphological properties (i.e., slope and area), land cover, and hydrological seasonality were examined to identify controlling factors and processes governing patterns of stream water quality in the upper Han River, China. Correlation analysis an...

The selectivity filter of the L-type calcium channel works as a Ca(2+) binding site with a very large affinity for Ca(2+) versus Na(+). Ca(2+) replaces half of the Na(+) ions in the filter even when these ions are present in 1 μM and 30 mM concentrations in the bath, respectively. The energetics of this strong selectivity is analyzed in this paper. We use Widom's particle insertion method to co...