The effects of nitrogenous synergists on the potentiometric responses to divalent transition metal ions were investigated concerning polymeric liquid membranes containing thenoyltrifluoroacetone (Htta) as an ionophore. The tested synergists were pyridine (py) and 4,4'-dioctyl-2,2'-bipyridyl (C8bpy). The potentiometric responses to metal ions, such as Cd2+, Co2+, Ni2+ and Zn2+, were induced by a...

Developing novel methods for metal-induced switching of peptide structures expands the design principles of functional biomolecules and biomaterials. Here, a simple method for on-resin synthesis of dipicolylamine (Dpa)-containing peptides was developed. Whereas addition of divalent metal ions such as Fe(ii) and Cu(ii) to a peptide bearing a pair of Dpa moieties at the i and i + 4 positions led ...

The assembly of ultrasmall metal nanoclusters (NCs) is of interest to both basic and applied research as it facilitates the determination of cluster structures and the customization of cluster physicochemical properties. Here we present a facile and general approach to assemble noble metal NCs by selectively inducing electrostatic interactions between negatively-charged metal NCs and divalent c...

The sorption behaviour of divalent cations M2+ (Cu, Pb and zn) and trivalent cations M3+ (Fe, Al) with humic acid isolated from oxidized coal (Hazro,se Anatolia,Turkey) was followed in aqueous solution. Coal humic acid and metal ion interaction was investigated with special emphasis on the effects of pH, metal ion concentration and humic acid concentration. it has been found that the interactio...

Proteins often require cofactors to perform their biological functions and must fold in the presence of their cognate ligands. Using circular dichroism spectroscopy. we investigated the effects of divalent metal binding upon the folding pathway of Escherichia coli RNase HI. This enzyme binds divalent metal in its active site, which is proximal to the folding core of RNase HI as defined by hydro...

Counterions are required for RNA folding, and divalent metal ions such as Mg(2+) are often critical. To dissect the role of counterions, we have compared global and local folding of wild-type and mutant variants of P4-P6 RNA derived from the Tetrahymena group I ribozyme in monovalent and in divalent metal ions. A remarkably simple picture of the folding thermodynamics emerges. The equilibrium f...

In the present study, an investigation on the complex formation between mono- and divalent metal ions (Na+, K+, Li+ and Mg2+) in the form of salt with different podands using various solvents has been carried out.  Isolated complexes were characterized by different spectroscopic techniques viz. IR, NMR and elemental analysis. On the basis of ...

The signal recognition particle (SRP) targets proteins to the endoplasmic reticulum in eukaryotes or to the inner membrane in prokaryotes by binding to hydrophobic signal sequences. Signal peptide recognition occurs within the highly conserved RNA-protein core of the SRP, underscoring the importance of this complex in SRP function. Structural analysis of the RNA and protein components of the pr...

Catalytic activity of four structural variants of the antigenomic delta ribozyme, two cis- and two trans-acting, has been compared in the presence of selected divalent metal ions that effectively support catalysis. The ribozymes differ in regions that are not directly involved in formation of the ribozyme active site: the region immediately preceding the catalytic cleavage site, the P4 stem and...