In this work, long optical path length thin‐layer electrochemical cell was constructed using indium‐tin oxide on glass as the electrode material. Iron release from ferritin adsorbed on the electrode was induced by applying a negative potential sweep in the presence of 1,10‐phenanthroline. The usefulness of spectroelectrochemistry as a means of determining the quantity of iron released from an adsorbed layer of ferritin is demonstrated. 相似文献
Attempts are made to efficiently decouple (13)C nuclei without significant loss of coherence during the application of the decoupling package. Such attempts are based on the S(3)E spin-state selection method. A newly developed double S(3)E (DS(3)E) is particularly efficient for C(alpha) detection for proteins as large as 480 kDa. 相似文献
In this paper, we summarise the development of off-axis electron holography on biological samples starting in 1986 with the first results on ferritin from the group of Tonomura. In the middle of the 1990s strong interest was evoked, but then stagnation took place because the results obtained at that stage did not reach the contrast and the resolution achieved by conventional electron microscopy.
To date, there exist only a few (12) publications on electron holography of biological objects, thus this topic is quite small and concise. The reason for this could be that holography is mostly established in materials science by physicists. Therefore, applications for off-axis holography were powerfully pushed forward in the area of imaging, e.g. electric or magnetic micro- and nanofields. Unstained biological systems investigated by means of off-axis electron holography up to now are ferritin, tobacco mosaic virus, a bacterial flagellum, T5 bacteriophage virus, hexagonal packed intermediate layer of bacteria and the Semliki Forest virus. New results of the authors on collagen fibres and surface layer of bacteria, the so-called S-layer 2D crystal lattice are presented in this review. For the sake of completeness, we will shortly discuss in-line holography of biological samples and off-axis holography of materials related to biological systems, such as biomaterial composites or magnetotactic bacteria. 相似文献
Experimental results of applying a steady magnetic field (20 and 30 mT) on agricultural plants reveal that their growth is more than that of control plants. Considering that these plants have ferritin cells, and each ferritin cell has 4500 Fe atoms, it is obvious that they have an outstanding role in the plants’ growth. As the last spin magnetic moment (SMM) of the Fe atom posed to an external magnetic field (EMF), the composition of SMM and EMF create an oscillator in the system. Then we have a moment of force on ferritin cells. This oscillator exerts its energy, then damps and finally locates in the field direction. The relaxed energy increased the internal temperature (i.e., the effective temperature of the magnetic spin system of plant) so that it is situated in a proper temperature for growing. This phenomenon (temperature increasing) occurs in the initial minutes of applying the magnetic field. So it depends on the number of times of locating the plant in magnetic field in a day (n). If this number (n) passes the critical value, the plant reaches a burning temperature and growth is perturbed. In this paper, the plant growth rate and critical temperature in a steady magnetic field were investigated and formulated theoretically. An innovative result in this research is as follows: if a plant's environment was in the dormant temperature, we could increase the internal temperature of the plant by applying a magnetic field n times in a day (for growth). 相似文献
Ferritin-immobilized poly(l-lysine)-modified electrodes showed well-defined redox waves representing ferritin. Cathodic and anodic peak currents obtained from cyclic voltammograms were proportional to potential sweep rates. From charge flow values during oxidation or reduction reactions calculated by peak areas in cyclic voltammograms, and the surface coverage of ferritin, reacted iron atoms per ferritin molecule were calculated. Obtained numbers of reacted iron atoms were significantly smaller than expected values from iron atoms at ferrihydrite core surfaces of ferritin, which would be caused by the rate-determining ion flow through ion channels of ferritin to compensate for charges in the ferritin cavity. Anodic and cathodic peak potentials in cyclic voltammograms were significantly dependent on cationic species in the solution, though voltammetric shapes and peak currents were independent of cations. From the obtained results that structural changes in ferritin were not detected by fluorescent spectra, it is thought that the cationic dependence on ferritin redox peak potentials is caused by ferritin cores. 相似文献
To probe into the potential of relieving the oxidative damage of salt stress, we investigated the protective role of nitric oxide on barley under salt stress. Salt stress resulted in increased ion leakage, lipid peroxidation and protein oxidation in barley leaves. Simultaneous treatments of barley leaves with 50 microM sodium nitroprusside, a nitric oxide donor, alleviated the damage of salt stress, reflected by decreased ion leakage, and malendialdehyde (MDA), carbonyl, and hydrogen peroxide content in barley leaves. The presence of the nitric oxide donor increased the activities of superoxide dismutases (SOD), ascorbate peroxidases (APX), and catalases (CAT). Meantime, sodium nitroprusside addition increased accumulation of ferritin at the protein level, indicating that nitric oxide directly regulated ferritin accumulation. These results suggested that nitric oxide can effectively protect seedlings from salt stress damage by enhancing activities of antioxidant enzymes to quench the excessive reactive oxygen species caused by salt stress and inducing the increase of ferritin accumulation to chelate larger number of ferrous ion. Information from this study can be used to improve soil management practices for sustainable use of salt-affected soils in the future. 相似文献