نتایج جستجو برای: zinc ion
تعداد نتایج: 274462 فیلتر نتایج به سال:
In the title complex, [ZnCl2(C13H17N3)], the coordination sphere of the zinc cation is distorted square pyramidal. The three N atoms of the N,N',N''-tridentate 8-[2-(di-methyl-amino)-ethyl-amino]-quinoline ligand and one chloride ion constitute a considerably distorted square base. The apical site is occupied by another chloride ion. The distortion from the ideal square-pyramidal geometry is ma...
Semisynthetic zinc chlorins are shown for the first time to self-assemble in the absence of an intrinsic hydroxy group, which is always present in the chlorosomal bacteriochlorophylls (BChl's) c, d and e. Instead, the presently studied compounds have carbonyl groups. These cannot function as hydrogen bond donating groups. However due to interspacing water molecules bound to the zinc ion, double...
Zinc is critical for a multitude of cellular processes, including gene expression, secretion and enzymatic activities. Cellular zinc is controlled by zinc-chelating proteins and by zinc transporters. The recent identification of zinc permeability of the lysosomal ion channel TRPML1 (transient receptor potential mucolipin 1), and the evidence of abnormal zinc levels in cells deficient in TRPML1,...
determination of uranium in natural water and complex solutions using ion exchange chromatography: a combined procedure using ion exchange chromatography and uv-vis spectrophotometry techniques has been developed to measure uranum in natural water and complex solutions. after conditicing , one hundred milli liters of sample solutions have been passed through an ion exchange column,pachked with ...
TACN (1,4,7-triazacyclononane) derivatives with three 6-methoxy-2-quinolylmethyl or 1-isoquinolylmethyl moieties were examined as fluorescent zinc sensors. Upon the addition of zinc, 6-MeOTQTACN (5) exhibited a 9-fold fluorescence increase at 420 nm (λex = 341 nm, ϕZn = 0.070). Fluorescence enhancement is specific for zinc and cadmium, although cadmium induces smaller increases (ICd/I0 = 3.6 an...
Zinc complex of L-carnosine (L-CAZ; generic name Polaprezinc) is the first drug for oral administration in which zinc plays an essential role. L-CAZ was approved as an anti-ulcer drug of membrane protection type. Characterization of L-CAZ was achieved by various spectroscopic methods along with elemental analysis. Zinc ion coordinates with L-carnosine to form a quadridentate 1:1 complex of poly...
We examined effects of heat, zinc, ion, and dithiothreitol in restoring the activity of lead-inhibited-5-aminolevulinate dehydratase (EC 4.2.1.24). The ratio of non-activated to activated activity produced by dithiothreitol correlated well with blood lead concentration among 35 lead workers. The individual effects of heat, zinc, or dithiothreitol differ from each other in the shift of pH optimu...
Extended x-ray absorption fine structure (EXAFS) spectroscopy was combined with thermodynamic and kinetic approaches to investigate zinc binding to a zinc finger (C2H2) and a tetrathiolate (C4) peptide. Both peptides represent structural zinc sites of proteins and rapidly bind a single zinc ion with picomolar dissociation constants. In competition with EDTA the transfer of peptide-bound zinc io...
Lobsters were fed cadmium-rich oysters for 28 days, and the induction of cadmium metallothionein and its relation to concentrations of cadmium, copper, and zinc in the digestive gland and gills was determined. A portion of the tissues also was retained for determining the cytosolic distribution of these metals by gel filtration and ion-exchange chromatography. The digestive gland contained a ma...
Regulation of metal ion homeostasis is essential to bacterial cell survival, and in most species it is controlled by metal-dependent transcriptional regulators. In this study, we describe a Corynebacterium diphtheriae ferric uptake regulator-family protein, Zur, that controls expression of genes involved in zinc uptake. By measuring promoter activities and mRNA levels, we demonstrate that Zur r...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید