The metalloisomerase glyoxalase I (GlxI) catalyses the conversion of methylglyoxal-glutathione hemithioacetal and related derivatives into the corresponding thioesters. In contrast with the previously characterized GlxI enzymes of Homo sapiens, Pseudomonas putida and Saccharomyces cerevisiae, we recently determined that Escherichia coli GlxI surprisingly did not display Zn2+-activation, but ins...

We demonstrate, for the first time, catalysis by Escherichia coli ribonuclease P (RNase P) RNA with Zn2+ as the sole divalent metal ion cofactor in the presence of ammonium, but not sodium or potassium salts. Hill analysis suggests a role for two or more Zn2+ ions in catalysis. Whereas Zn2+ destabilizes substrate ground state binding to an extent that precludes reliable Kd determination, Co(NH3...

This review summarizes the evidence that apoptosis is m odulated by intracellular excess or deficiency of Zn2 + , considers mechanisms whereby Zn2+ may influence apoptosis, and delineates gaps in current knowledge and opportunities for research. The experimental evidence supports four major conclusions: [1] Z inc deficiency, resu lting from dietary deprivation of m ice, or exposure of cultured ...

In the central nervous system, glycine is a co-agonist with glutamate at the N-methyl-D-aspartate subtype of glutamate receptors and also an agonist at inhibitory, strychnine-sensitive glycine receptors. The GLYT1 subtypes of glycine transporters (GLYTs) are responsible for regulation of glycine at excitatory synapses, whereas a combination of GLYT1 and GLYT2 subtypes of glycine transporters ar...

BACKGROUND Recombinant whole-cell sensors have already proven useful in the assessment of the bioavailability of environmental pollutants like heavy metals and organic compounds. In this work 19 recombinant bacterial strains representing various Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli, Pseudomonas fluorescens) bacteria were constructed to ...

Zn2+ ions were found to efficiently inhibit activated protein C (APC), suggesting a potential regulatory function for such inhibition. APC activity assays employing a chromogenic peptide substrate demonstrated that the inhibition was reversible and the apparent K I was 13 +/- 2 microM. k cat was seven fold decreased whereas K M was unaffected in the presence of 10 microM Zn2+. The inhibitory ef...

To elucidate the molecular mechanisms underlying neuronal death after transient forebrain ischemia, we cloned genes expressed after transient forebrain ischemia in the Mongolian gerbil by a differential display method. A gerbil homolog of rat zinc transporter, ZnT-1, which transports intracellular Zn2+ out of cells, was isolated. Its expression became detectable exclusively in pyramidal neurons...

Of group 12 metals, zinc is an essential element to maintain our life, but other metals such as cadmium and mercury are toxic in cellular activities. Interactions of these metals with biomembranes are important to understand their effects on our living cells. Here, we describe the membrane perturbations induced by these metals in human erythrocytes. Of these metals, Zn2+ ions only induced the e...

The construction and performance characteristics of a novel chromate ion-selective membrane sensor are described and used for determining chromium(III) and chromium(VI) ions. The sensor is based on the use of a rhodamine-B chromate ion-associate complex as an electroactive material in a poly(vinyl chloride) membrane plasticized with o-nitrophenyloctyl ether as a solvent mediator. In a phosphate...