Effects of monovalent cations on the neutral rabbit liver fructose-1,6-bisphosphatase are multifunctional and dependent on their nonhydrated ionic size. (a) The maximal velocity is increased by addition of monovalent cations with the optimum stimulation occurring with a nonhydrated ionic radius of 1.2 A in the presence of a chelating agent such as EDTA. (B) Activation curves are sigmoidal with ...

The symbiosome of nitrogen fixing root nodules mediates metabolite exchange between endosymbiotic rhizobia bacteria and the legume host. In the present study, the ion currents of the symbiosome membrane of the model legume Lotus japonicus were analyzed by patch-clamp recording. Both excised and symbiosome-attached patches exhibited a large inward (toward the cytosolic side of the membrane) curr...

in this study, we assessed the relative contribution of organic and inorganic solutes to osmotic adjustment (oa) in three almond rootstocks subjected to four levels of soil salinity. the results showed that leaf water and osmotic potentials were affected by salinity in gf677 and bitter almond, but less so in gn15, suggesting a higher selectivity for k+ and ca2+ against na+ in this latter rootst...

We observed the nonenzymatic formation of guanosine 3’:5’-monophosphate (cyclic GMP) from GTP. The reaction was dependent upon heat and was accelerated by divalent cations and creatine phosphate. The formation of cyclic GMP was greater with increased incubation time, temperature, GTP concentration, and pH. All of the divalent cations tested (Mg2+, Mnz+, Ca2+, Ba2+, and Znzf) increased cyclic GM...

The radial distribution of monovalent cations surrounding spherical nucleic acid-Au nanoparticle conjugates (SNA-AuNPs) is determined by in situ small-angle x-ray scattering (SAXS) and classical density functional theory (DFT) calculations. Small differences in SAXS intensity profiles from SNA-AuNPs dispersed in a series of solutions containing different monovalent ions (Na(+), K(+), Rb(+), or ...

Molecular dynamics simulation (MD) has been done for a molten (Li, K)C1 mixture of the eutectic composition at about 700 K, 950 K and 1100 K and, for comparison, also for pure LiCl and KCl at about 950 K and 1100 K The atomic masses of half the Li and K ions have been set at 6.941 and 39.098, respectively. Self-exchange velocities (SEVs) of these cations have been calculated. The Chemla effect ...

Pyruvate kinase (EC 2.7.1.40) is inhibited by phenethylbiguanide. The kinetics of inhibition are competitive between biguanide and divalent, but not monovalent, metal cation activators of the enzyme; biguanide inhibition thus resembles inhibition by Ca(++). Alteration of either the polar or nonpolar portion of the phenethylbiguanide molecule quantitatively reduces its effectiveness as an inhibi...

This study reveals that, in strong coulomb coupling regime, bending a straight and fully overcharged DNA (up to its ‘maximal acceptance’ by multivalent cations) to a circle releases some of the adsorbed (correlated) cations but still remains fully overcharged. This phenomenon seems to be inherent to the minimum energy state of a DNA. By definition, the total electrostatic potential energy of a ...