The interaction between eriochrome black T and Li , Na , K ,Mg and Ca ions in acetone and dimethylsulphoxide solutions has been investigated spectrophotometrically. The formation constants of the resulting 1 : 1 complexes were determined and found to decrease in the order Mg >Ca >Li >K >Na in both solvents used. There is an inverse relationship between the stabilities of the complexes...

The quadruplex structures of the human telomere sequences AG3(T2AG3)3 I and (T2AG3)4 II were investigated in the presence of Na+ and K+ ions, through the cross-linking of adenines and guanines by the cis- and trans-[Pt(NH3)2(H2O)2](NO3)2 complexes 1 and 2. The bases involved in chelation of the cis- and trans-Pt(NH3)2 moieties were identified by chemical and 3'-exonuclease digestions of the pro...

Na+:K+:2Cl- cotransporters (NKCCs) belong to the SLC12A family of cation-coupled Cl- transporters. We investigated whether enamel-producing mouse ameloblasts express NKCCs. Transcripts for Nkcc1 were identified in the mouse dental epithelium by RT-qPCR and NKCC1 protein was immunolocalized in outer enamel epithelium and in the papillary layer but not the ameloblast layer. In incisors of Nkcc1-n...

Salinity is a major problem confronting agriculture in arid environments. Sensitivity to high levels of salt in plants is associated with an inability to effectively remove Na ions from the cell cytoplasm. The ability to compartmentalize Na may result, in part, from stimulation of the H -ATPases on the plasma membrane (PM-ATPase) and vacuolar membrane (V-ATPase). These H -pumping ATPases may pr...

The role of the electrogenic Na(+)-Ca(2+)-exchange mechanism in regulating the spike activity of the ureter was studied. The ureter cells were shown to be capable of generating action potentials (AP) in sodium-free Krebs solution. The time during which the spikes are generated is in exponential dependence on the concentration of calcium ions in the medium, [Ca2+]o within 2.5 to 15 mmol/l. Simul...

Studies have been carried out on movements of Ca and Sr ions in rat small intestine, using the in vivo preparation developed by Curran and Solomon (5). In the concentration range of 0 to 25 mM, Sr flux appears to be passive, though restricted. Ca transport may not, however, be ascribed to passive independent movement of these ions since at higher concentrations (12.5 and 25 mM) Ca return from b...

soil salinity affects ions concentrationss of plant tissues and this may alter the merits quality of medicinal plants. experiments were conducted during 2003 at the the isfahan university of technology campus, isfahan, iran, to assess the effects of five soil salinity levels (3.2, 3.6, 4.5, 5.4 and 7.5 ds m-1) on na, k, and ca contents of borage and echium. each plant species was studied in a s...

The asymmetric unit of the title compound, {[Na(C(6)H(12)O(6))(2)]Cl}(n), contains six glucose mol-ecules, three Na(+) ions and three Cl(-) ions, i.e. three independent {[Na(C(6)H(12)O(6))(2)]Cl} units. Each of these units forms polymeric chains along the c axis. Each Na(+) ion is surrounded by six O atoms from four glucose mol-ecules, forming a distorted octa-hedral geometry. All glucose mol-e...

The dissociation reactions of [M + H]+, [M + Na]+, and [M + Cu]+ ions of bradykinin (amino acid sequence RPPGFSPFR) and three bradykinin analogues (RPPGF, RPPGFSPF, PPGFSPFR) are examined by using 193-nm photodissociation and post-source decay (PSD) TOF-TOF-MS techniques. The photodissociation apparatus is equipped with a biased activation cell, which allows us to detect fragment ions that are ...

The effect of Pb(2+) ions on the Na(+),K(+)-ATPase was investigated in detail by means of steady-state fluorescence spectroscopy. Experiments were performed by using the electrochromic styryl dye RH421. It is shown that Pb(2+) ions can bind reversibly to the protein and do not affect the Na(+) and K(+) binding affinities in the E(1) and P-E(2) conformations of the enzyme. The pH titrations indi...