The interaction of ribonuclease A with cupric and zinc ions has been studied spectrophotometrically and by potentiometric titration in the presence and absence of cytidylic acid derivatives. In the absence of cytidylic acid, the results suggest that each cupric ion distributes among a set of approximately four spectrally similar sites; each site appears to consist mainly of a single imidazole s...

In order to investigate the functions of reductones, their mutagenic action was studied with and without cupric ion using Salmo nella typhimurium TA 100 strain. Triose reductone (TR), which has the simplest enediol structure among reductones, induced a notable frequency of his+ revertants at 2.5 or 5mM. The addition of cupric ion to TR at a molar ratio of 1:1,000 lowered the most active concent...

The effect of 2’-cytidylic acid and 3’qtidylic acid upon the binding of cupric ions by RNase has been studied by gel filtration, together with the effect of cupric ions upon binding of 2’and 3’-cytidylic acids. The results confirm that binding of 2’-CMP by RNase weakens its athnity for cupric ions; reciprocally, binding of cupric ion diminishes the athnity of RNase for 2’CMP. The negative inter...

In this paper, cupric oxides was found to effectively oxidize levulinic acid (LA) and lead to the decarboxylation of levulinic acid to 2-butanone. The effects of cupric oxide dosage, reaction time and initial pH value were investigated in batch experiments and a plausible mechanism was proposed. The results showed that LA decarboxylation over cupric oxides at around 300 °C under acidic conditio...

Crab zoeae (Rhithropanopeus harrisii) were exposed during their development opment to a range of free cupric ion activities regulated in seawater by use of a copper chelate buffer system. Most cytosolic copper was found to be associated with metallothionein. Copper-thionein could be related to free cupric ion activity, and a shift in copper-thionein accumulation was correlated with inhibition o...

To enhance the field persistency of S. litura nuclear polyhedrosis virus (SLNPV), three chemicals viz. cupric ammonium nitrate, tinopal and cupric sulphate were tried as protectants (0.01 mg/ml) against natural sunlight (UV) irradiation. On exposure for 8 hr and subsequent bioassaying (diet surface treatment), it was found that cupric sulphate protected the polyhedrosis inclusion bodies (PIBs),...

Isoflavones are commonly consumed in many Asian countries and have potentially positive effects on human being. Only a few and rather controversial data on their interactions with copper and iron are available to date. 13 structurally related isoflavones were tested in the competitive manner for their Cu/Fe-chelating/reducing properties. Notwithstanding the 5-hydroxy-4-keto chelation site was a...

The mechanisms and spectroscopic properties generated by intermediate states upon cupric ion binding to flexible peptide motifs in proteins are of considerable interest. One such motif is the Cys-X-X-X-Cys motif characteristic to members of the Sco family of proteins. In the antibiotic producing bacterium, Streptomyces lividans, a role for its Sco protein (Sco(Sl)) as a cupric metallochaperone ...

Levulinic acid (LA), 4-oxo-pentanoic acid, is a new platform chemical with various potential uses. In this paper, catalytic hydrogenation and oxidation of levulinic acid were studied. It was shown from experiments that levulinic acid can be hydrogenated to γ-valerolactone (GVL) over transition metal catalysts and oxidative-decarboxylated to 2-butanone (methyl-ethyl-ketone, MEK) and methyl-vinyl...

Male commercial broiler strain chickens were fed either a control diet (based on corn and soybean meal) or the control diet supplemented with cupric sulfate pentahydrate or cupric citrate in seven experiments (six in floor pens, one in wire-floored batteries). In Experiment 1, feeding 125 or 250 mg/kg copper increased growth (4.9%) and decreased feed conversion ratios (3.4%), total plasma chole...