Although Mg2+ is an important cofactor for the specific degradation of RNA by ribozymes, it is not considered as a typical chemical nuclease. In this study we show that in combination with common buffers such as tris(hydroxymethyl)aminomethane and sodium borate, Mg2+ is a powerful catalyst for the degradation of RNA. pH and temperature are found to be the principal factors for the efficient deg...

The rates of H-D exchange for imino and amino protons in adenosine, calf thymus DNA, poly (dA-dT), poly(dG-dC), and poly (dG-me5dC) were determined using stopped flow kinetic methods in the presence of various concentrations of Tris, imidazole, Mg2+, and spermine in citrate buffer (pH 7, 25 degrees C). CD spectroscopic studies showed that all polynucleotides always remain in the B-form under th...

The short term regulation of fatty acid biosynthesis has been studied using primary cultures of human shin fibroblasts. These cells show rapid changes in rates of acetate incorporation into fatty acids depending upon the lipid content of the medium. When cells are incubated in medium containing lipid-deficient fetal calf serum overnight and then are switched to Eagle’s minimum essential medium,...

A simple colorimetric assay with high sensitivity, excellent selectivity and a tunable dynamic range is reported for detecting trace amounts of mercuric ion in aqueous solution based on the coordination of Hg(2+) to the gold nanoparticle (AuNP)-associated 3-nitro-1H-1,2,4-triazole (NTA). The NTA can stabilize the AuNPs against tris-induced aggregation through capping the AuNPs. In the presence ...

The plasma membrane of Listeria monocytogenes strain 42 was prepared by osmotic lysis of protoplasts with tris(hydroxymethyl)aminomethane (Tris) buffer, pH 8.2, containing MgCl(2) and glucose, followed by washing with NaCl and MgCl(2) in Tris buffer. Electron microscopy showed that the preparation was not contaminated with cytoplasmic material. The membrane preparation was composed of 55 to 60%...

The enzymatic degradation of polyethylene terephthalate (PET) occurs at mild reaction conditions and may find applications in environmentally friendly plastic waste recycling processes. The hydrolytic activity of the homologous polyester hydrolases LC cutinase (LCC) from a compost metagenome and TfCut2 from Thermobifida fusca KW3 against PET films was strongly influenced by the reaction medium ...

Effects of D 600, papaverine and KCN on sustained contracture induced by 20 mM KCl in a Na+-free sucrose- or Tris-substituted solution were investigated in the taenia coli of guinea pigs. D 600 (10(-5) M) and papaverine (10(-4) M), added after 40 min incubation in the 20 mM KCl sucrose solution, relaxed the muscle by 88.2 +/- 8.0% (mean +/- S.E., n = 4) and 78.8 +/- 6.3% (n = 4), respectively. ...

Solubilisation of myofibrillar proteins in physiological or low ionic strength solutions is essential for their utilisation as supplementary protein food. In order to achieve low ionic strength solubility, ultrasonication as a physical force has been introduced as an effective method to shift the solubility range of myofibrillar proteins from high to low ionic medium. In this study, change in t...

Everted sacs of rat duodenum and ileum were used to study the effect of anions and organic ligands on the absorption of zinc. The uptake per unit weight of tissue was greater in duodenum than ileum, and it was influenced by the Zn concentration and pH of the incubation medium. The Zn uptake from inorganic salts in simple buffered medium varied in the order zinc sulphate greater than zinc chlori...

MUSTARD,, J .FRASER,DENNIS W .YERRY, RAELENE L. KINLOUGHRATHBONE, AND MARIAN A. PACKHAM. Factors resfonsible for ADPinduced release reaction of human platelets. Am. J. Physiol, 228(6) : 17571765. 1975,-Extensive aggregation of human platelets can be induced by ADP without secondary aggregation or release of granule contents. This occurs with washed platelets in Tyrode solution containing 0.35 Y...