Human JL-calpain is activated maximally by 100-200 JLM Ca2+. Both the 80 kDa and 29 kDa subunits of JL-calpain have a EF-hand type calcium-binding domain. It is known that trivalent terbium ion (Tb3+) mimics Ca2+ in many biological systems. We found that Tb3+ alone transiently activated calpain. However, in the presence of Ca2+ , Tb3+ inhibited JL-calpain with an IC5o of about loo JLM. As high ...

Herein we describe the synthesis and luminescence of nanosized (Lu1-y-xGdx)2O2S:Tby and (Lu1-y-xGdx)2O3:Tby phosphors with y = 0.1 mol% Tb3+ and y = 2 mol% Tb3+ and x ranging between 0 and 1. The concentration of Gd3+ (x) was varied in steps of 0.1 (molar ratio Gd3+). The samples at 0.1 < x < 0.7 contained a mixture of (Lu1-xGdx)2O3:Tb3+ and (Lu1-xGdx)2O2S:Tb3+, while the samples at x = 0 conta...

YF3:Ce3+, YF3:Tb3+, and YF3:Ce3+/Tb3+ nanocrystals were synthesized by an ethylenediaminetetraacetic acid (EDTA)-assisted hydrothermal method and characterized by X-ray diffraction and scanning electron microscope. In the excitation spectra, there is one broad excitation band at 285 nm for YF3:Ce3+ and 255 nm for YF3:Tb3+, which are related to the f-d excitations of the Ce3+ and Tb3+ in the hos...

Terbium doped Y2O3 planar waveguides were fabricated by sol–gel process and dip-coating using yttrium acetate as precursor. Two different doping modes were compared, i.e. introduction in the sol of dispersed Tb3+ions from dissolved Tb(NO3)3, or of nanoparticles of Tb2O3 or [Y2O3:50% Tb] from an alcoholic suspension. The chemical and nanostructural properties were analyzed by infrared spectrosco...

apotransferrin (apo tf)  in 0.1 m n-(2hydroxyethyl)piperazine-n2-ethanesulfanic acid at 25 ˚c  and ph 7.4 has been titrated with acidic solution of tb3+. the binding of tb3+ at  the two specific metal-binding sites of transferrin was followed from the changes in the difference uv spectra at 245 nm. the molar absorptivity per binding site for tb3+-tf is 22,500 ± 1000 m-1cm-1. to determine the tb...

Terbium was used as a probe of Ca2+-binding sites on the prothrombin-phospholipid complex. Stoichiometric titrations of prothrombin binding to phospholipid vesicles with either Tb3+ or Ca2+ showed that a minimum of 8 metal ions were needed for binding prothrombin to vesicles (3 Mn2+ + 5 Ca2+ for prothrombin or 8 Tb3+ for F-1). When Ca2+ alone was used, a total of about 11 metal ions were needed...

Nano- and microceramics of Gd3Ga5O12 garnet doped with 1 mol % Tb3+ ions were synthesized via co-precipitation and high-temperature solid-state reaction methods. X-ray diffraction measurements confirmed the formation of the garnet structure with Ia3d space group in all investigated samples. Atomic force microscopy surface images and grain-size distribution diagrams of Gd3Ga5O12: 1 mol % Tb3+ na...

Herein the preparation and cathodoluminescence of nanoparticles of cubic Y2O3:Tb3+ having Tb3+ concentration varying between 0.1 and 10 Mol% are described. The cathodoluminescence spectra were recorded with a high resolution spectrometer, which enabled the identification of Tb3+ lines with C2 and S6 symmetry: the lines at 542.8 nm and 544.4 nm were designated as D4→F5 (C2) and D4→F5 (S6) respec...