Neuronal growth-inhibitory factor (GIF), a central-nervous-system-specific metallothionein-like protein, has been isolated by means of an improved isolation procedure from bovine brain. The native protein contains 4-5 Cu+ and 2-2.5 Zn2+, which results in an overall stoichiometry of 6-7 mol metal ions/mol protein. Native Cu, ZN-GIF and the Zn2+ -substituted and Cd2+-substituted metalloforms have...

1. The inflow of Mn2+ across the plasma membranes of isolated hepatocytes was monitored by measuring the quenching of the fluorescence of intracellular quin2, by atomic absorption spectroscopy and by the uptake of 54Mn2+. The inflow of other divalent metal ions was measured using quin2. 2. Under ionic conditions which resembled those present in the cytoplasmic space, Mn2+, Zn2+, Co2+, Ni2+ and ...

In rats, of the Wistar-Porton strain, a single intravenous injection of 1.25 mg Cd2+ between days 9 and 15 of gestation results in a high incidence (80% of hydrocephalus, together with other malformations in the fetuses, examined on day 20. This dose is critical, since 1.1 mg Cd2+/kg is not teratogenic, while 1.35 mg Cd2+/kg kills all the embryos. Intravenous injection of Cd2+ to the pregnant r...

Monovalent and divalent cations competitively displace tetrodotoxin and saxitoxin (STX) from their binding sites on nerve and skeletal muscle Na channels. Recent studies of cloned cardiac (toxin-resistant) and brain (toxin-sensitive) Na channels suggest important structural differences in their toxin and divalent cation binding sites. We used a partially purified preparation of sheep cardiac Na...

Tat, the transactivating protein from HIV, forms a metal-linked dimer with metal ions bridging cysteine-rich regions from each monomer. This novel arrangement is distinct from the "zinc finger" domain observed in other eukaryotic regulatory proteins. Ultraviolet absorption spectra show that Tat binds two Zn2+ or two Cd2+ ions per monomer, and electrophoresis of the Tat-metal complexes demonstra...

A selective and sensitive derivative photometric method has been developed for the determination of trace amounts of Zn2+ with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol in the presence of cetylpyridinium chloride, a cationic surfactant. The molar-absorption coefficient and analytical sensitivity of the 1:2 complex at 554 nm are 1.19 x 10(5) L mol(-1) cm(-1) and 0.56 ng mL(-1), respectively....

Water-soluble CdTe quantum dots (QDs) have been utilized as photoluminescence probes for the detection of metal ions such Pb2+, Hg2+, Cd2+, etc. We initially developed highly (PL) Zn-doped toxic detection. A study on changes optical properties and QDs when exposed to Pb2+ suggested that could act a surface passivating agent reduce Te2- dangling bonds while Zn2+ dopant stabilizes against ambient...

Helix-coil transition of poly aspartic acid (PASP) was investigated by dc polarography in the presence of Cd2+ and/or Zn2+ as a detecting marker which attached to the polymer. The diffusion currents (id) of Cd2+ and Zn2+ decreased sharply in the pH range of 3.5-7.0 due to the formation of the metal ions-PASP macromolecular complexes. The complex formation revealed on an increase in the magnitud...