Metal complexes of divalent Nickel and Cobalt metal ions have been synthesized with picolinic acid hydrazide (PH) , ortho -hydroxy acetophenone picolinoyl hydrazone ( APH) ortho-hydroxy iso-nicotinoyl (AIH) ligands were isolated at both high pH low pH. These characterized by elemental analyses also electronic spectral studies magnetic measurements. Ligands PH AIH act as tridentate, while APH is...

Metallothioneins (MTs) constitute a universal family of polymorphic, ubiquitous small Cys-rich metal-binding polypeptides that in mammals are represented by four highly similar isoforms (MT1 to MT4). MT1 and MT2 have generally been considered as equivalent proteins, so that they are commonly referred to as MT1/MT2. However, transcription data have suggested a differential behavior for both gene...

Environmental remediation requires ion-selective polymers that operate under a wide range of solution conditions. In one example, removal of trivalent and divalent metal ions from waste streams resulting from mining operations before they enter the environment requires treatment at acidic pH. The monoethyl ester phosphate ligands developed in this report operate from acidic solutions. They have...

Mitochondrial iron uptake is of key importance both for organelle function and cellular iron homoeostasis. The mitochondrial carrier family members Mrs3 and Mrs4 (homologues of vertebrate mitoferrin) function in organellar iron supply, yet other low efficiency transporters may exist. In Saccharomyces cerevisiae, overexpression of RIM2 (MRS12) encoding a mitochondrial pyrimidine nucleotide trans...

To systematically study the effects of the number of d electrons of the first transition metal ions (Fe, Co, Ni, Cu and Zn) on the formation and stability of metal flavonoid complexes, we took the quercetin/M2+ complex as a model system to investigate the structures and properties of these complexes. Based on considerable structural information obtained through ESI-MSn, all of the first transit...

Hollow metal oxide nanocrystals were prepared by etching cuprous oxide with metal ions and were applied as photoelectrodes. As a hard template, polyvinylpyrrolidone stabilized cuprous oxide (PVP-Cu2O) and non-stabilized cuprous oxide (nPVP-Cu2O) were synthesized by a precipitation method. Hollow iron oxide and cobalt oxide nanocrystals with a truncated octahedral morphology were fabricated by a...

A semiconductor to metal transition (SMT) occurs either as a function of composition or external pressure in the TmSe-TmTe and TmSe-EuSe pseudobinary com ounds. The transition is caused by the delocalization of electrons from the 4flq shell of divalent Tm into the 5d conduction band. The divalent configuration (4f7) of the Eu ions is more stable and therefore is not involved in the SMT. A strik...

The surface pressure-area curves of synthetic (dipalmitoyl), egg, and yeast lecithins showed that the limiting areas depend on the degree of unsaturation of the fatty acid residues (dipalmitoyl < egg < yeast lecithin). The surface potential of phosphatidal choline (240 mv) was lower than that of the dipalmitoyl lecithin (380 mv), both at 60 A2/molecule. This difference in surface potentials is ...

Incorporation of divalent metal ions into an active site is a fundamental catalytic tool used by diverse enzymes. Divalent cations are used by protein kinases to both stabilize ATP binding and accelerate chemistry. Kinetic analysis establishes that Cyclin-dependent kinase 2 (CDK2) requires simultaneous binding of two Mg(2+) ions for catalysis of phosphoryl transfer. This tool, however, comes wi...

Sequence-specific binding of divalent cations to nucleosomal DNA can potentially influence nucleosome position and mobility, as well as modulate interactions with nuclear factors. We define the bonding and specificity of divalent cation interaction with nucleosomal DNA by characterizing Mn2+ binding in the x-ray structure of the nucleosome core particle at 1.9-A resolution. Manganese ions are f...