Formation of spatially periodic patterns is a ubiquitous process in nature and man-made systems. Periodic precipitation the oldest type pattern formation, which formed colloid particles are self-assembled into sequence separated zones solid hydrogels. Chemical systems exhibiting mostly comprise oppositely charged inorganic ions. Here, we present new sub-group this phenomenon driven by diffusion...

The influence of divalent cations (Cd2+, Zn2+, Sr2+) and staphylococcus protein A on the superprecipitation reaction of cardiac muscle actomyosin was investigated using methods of preparative protein chemistry, optical spectroscopy and mechanokinetic analysis. It was shown that the metal ions in the range of concentrations 0.1–5 mM inhibit the Mg2+-dependent SPP reaction of actomyosin cardiac m...

A time-dependent inhibition of the thyrotropin-releasing-hormone (TRH)-degrading ectoenzyme (EC 3.4.19.-) from rat brain by the metal-complexing agents imidazole, NaCN, EDTA and 1,10-phenanthroline could be demonstrated. In contrast, the inhibition by the non-chelating analogues 4,7and 1,7-phenanthroline was not time-dependent. At a concentration of 100 ,M EDTA the enzymic activity decreased by...

Alcohol acetyltransferase (AATase) catalyzes the esterification of isoamyl alcohol by acetyl coenzyme A. The enzyme was solubilized from the microsomal fraction of Saccharomyces cerevisiae Kyokai No. 7, using Triton X-100 and then purified by a series of chromatographic separations: Poly Buffer Exchanger 94 (PBE94), DEAE Toyopearl, Toyopearl HW60, hydroxyapatite, Octyl-Sepharose CL-4B, and hexa...

In Alcaligenes eutrophus CH34, determinants encoding inducible resistance to chromate (chr) and to cobalt and nickel (cnr) are located adjacent to each other on plasmid pMOL28. To develop metal-sensing bacterial strains, a cloned part of plasmid pMOL28, which contains both determinants, was mutated with Tn5-lacZ. The chr::lacZ fusions were specifically induced by chromium; cnr was induced best ...

The purpose of this work was to synthesize and characterize the thiatetraaza macrocycle 1-thia-4,7,10,13-tetraazacyclopentadecane ([15]aneN4S). Its acid-base behaviour was studied by potentiometry at 25 °C and ionic strength 0.10 M in KNO3. The protonation sequence of this ligand was investigated by 1H-NMR titration that also allowed the determination of protonation constants in D2O. Binding st...

Recent discoveries in zinc biology provide a new platform for discussing the primary physiological functions of mammalian metallothioneins (MTs) and their exquisite zinc-dependent regulation. It is now understood that the control of cellular zinc homeostasis includes buffering of Zn2+ ions at picomolar concentrations, extensive subcellular re-distribution of Zn2+, the loading of exocytotic vesi...

We have synthesized an 18-amino acid peptide that contains the cysteine-rich region of the tat protein from human immunodeficiency virus. Previous experiments in vitro with the intact tat protein have shown that these cysteines serve as metal ligands, causing tat to form metal-linked dimers. Ultraviolet absorption spectra show that the synthetic peptide (tat21-38) binds two Cd2+ or two Zn2+ ion...

bTyrosine 401 of the skeletal muscle isoform (mu 1) of the rat muscle Na channel is an important determinant of high affinity block by tetrodotoxin (TTX) and saxitoxin (STX) in Na-channel isoforms. In mammalian heart Na channels, this residue is substituted by cysteine, which results in low affinity for TTX/STX and enhanced sensitivity to block by Zn2+ and Cd2+. In this study, we investigated t...

the complexation reactions between methylthymol blue (mtb) and co2+, ni2+, cu2+, zn2+ and pb2+ ions have been studied in different water-methanol mixtures at ph 4.45 and 25 °c by a spectrophotometric technique. the stepwise stability constants of the resulting 1:1 and 2:1 (metal ion to ligand) complexes were determined from the absorbance-mole ratio data. it was found that the overall stability...