Quantitative Assessment of the Effects of Reducing Agents on Biological Macromolecules and on the Possible Repair of Oxidative Damage

Objective. To quantitatively assess the influence of reducing agents on biological macromolecules and on the possible repair of oxidative damage. Methods. Samples (antibody, enzyme, DNA, and diluted serum) were treated with reducing agents (ammonium ferrous sulfate, ascorbic acid, potassium iodide, and sodium hyposulfite) in the experimental group and with NaCl in the control group. Enzyme-linked immunosorbent assay and quantitative PCR were used to determine the activity of antibody, enzyme, and DNA. Native gel electrophoresis (Native-PAGE) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) were used to determine protein structure. Reducing agents that had no inhibitory effect on biological macromolecules were selected. Antibodies were treated with oxidants to caused oxidative damage and then treated with reducing agents, and the possible repair of oxidative damage was assessed. Results. Certain concentrations of ammonium ferrous sulfate resulted in significant inhibition of antibody, enzyme, DNA, and diluted serum. Certain concentrations of ascorbic acid resulted in significant inhibition of antibody. Sodium hyposulfite and potassium iodide had no effect on antibody, enzyme, DNA, and diluted serum. The OD values in group A (in which HBsAb was treated by oxidation and then a reductant) were significantly higher than those in group B (HBsAb treated by oxidation). Conclusion. Ammonium ferrous sulfate, ascorbic acid, sodium hyposulfite, and potassium iodide had different effects on antibody, enzyme, DNA, and diluted serum. The reduction in antibody activity due to an oxidant was partially repaired by a reductant.

Dyeing of Pearl Fiber by Walnut Peel Dye

This paper studied the metachrome process of an optimal dyeing method by comparing the color and fastness of walnut peel extract applied on the pearl fiber with ammonium ferrous sulfate as mordent. In addition, the paper also ascertained the reasonable dyeing process, that is, pH 9, walnut peel extract (the dye) dosage 200 ml/L, mordant (ammonium ferrous sulfate) 2.5 g/L, temperature 80 °C, time 60 min and liquor ratio 1:30, through analysis on single-factor experiments and orthogonal experiments by taking K/S as an evaluation index for the dyeing effect. The results showed that a better effect is achievable by dyeing the pearl fiber with walnut peel dye through the metachrome process.

Determination of Vanadium Valency in Roasted Stone Coal by Separate Dissolve-Potentiometric Titration Method

ABSTRACTStone coal is an important vanadium-bearing resource in China. Most vanadium exists in stone coal as V(III), which is stable and not easily to be extracted. The V(III) should be oxidized to V(IV) and/or V(V) by roasting with additives at high temperature and then extracted by acid leaching and/or water leaching. Hence, the vanadium valency in roasted stone coal can reflect the roasting efficiency and leaching rate. In traditional digestion process, the V(V) can oxidize V(III) in solution and this causes great error to the determination of vanadium valency. In this study, the V(IV) and V(V) in roasted stone coal is dissolved firstly in 5% of hydrochloric acid at room temperature for 1h because the V(III) embedded in crystal lattice can not dissolve in dilute acid. The acid solution containing V(IV) and V(V) is titrated by 0.02 M ammonium ferrous sulfate (AFS), and the jump in titration curve indicates the reducing of V(V) to V(IV) by ferrous ion. The volume of V(V) can be calculated according to the consumption of AFS. The total volume of vanadium can be determined by potassium permanganate oxidation-ammonium ferrous sulfate titrimetric method. Hence, the volume of V(IV) can be obtained by deducting the quantity of V(V) from the total vanadium. Secondly, the undissolved residue is digested in Teflon vessel by phosphoric acid and hydrofluoric acid at 90 °C for 2h. The digestion solution is also titrated by AFS under nitrogen atmosphere, and the jump in titration curve denotes the reducing of V(IV) to V(III) by ferrous ion in phosphoric acid medium. So, the volume of V(III) and V(IV) can be obtained in the same way. This method is characterized by high measuring accuracy and excellent reproducibility.

Research of Immobilization of Transglutaminase on Polypropylene Microporous Membranes

Activated ozone as the carrier，crylic acid as the monomer and glutaraldehyde as the cross-linking agent were used to research the immobilization of transglutaminase on polypropylene microporous membranes. The effect of ozone activation time，grafting time，grafting temperature，monomer concentration and ammonium ferrous sulfate concentration on grafting degree were studied, the Immobilization conditions were also studied. We found the optimal reaction conditions as following: consistency of hexamethylendiamine was 15%，at 50°C for 120min and consistency，at 30°C for 45minites，consistency of enzyme was 15mg/mL at 4°C. So the immobilized amount of protein could come to 30.23mg/g membrane and the activity of immobilized MTG come to 16.9U/g membrane.