In this contribution, we examine the effect of promoter´s ionic charge and valence orbital energy on catalytic activity Fe-based catalysts, based in situ synchrotron X-ray powder diffraction (SXRPD), temperature-programmed-based techniques (TPR, TPD, CO-TP carburization), Fischer–Tropsch synthesis testing studies. We compared promoting effects K (a known promoter for longer-chained products) wi...

Using K+-specific microelectrodes in the isolated retinal pigment epithelium preparation from frog eye, we have examined changes in extracellular K+ in the unstirred layer between the choroid and basal membrane. We found, using agents to depolarize apical and basal membranes, that membrane potential modulates K+ efflux from the basal membrane into the choroid. [K+] in the choroid was found to b...

Synaptic inhibition mediated by the activation of potassium channels has been reported from several types of neurons. In each case, despite mediation by different neurotransmitters, the K+ conductance underlying the synaptic potential is activated by a G protein and inwardly rectifies. We report here a second K+ current that contributes to synaptic inhibition. Intracellular recordings were made...

BACKGROUND EF-hand proteins can be activated by the binding of various heavy metals other than calcium, and such complexes can disturb the calcium-signaling pathway and cause toxicity and disease causing state. So far, no comprehensive study has been done to understand different heavy metals binding to calcium signaling proteins. RESULTS In this work, the flexibility of the EF-hand motifs are...

As with other guanine-rich sequences, poly[d(GGA)], poly[d(GA)] and poly[d(GAA)] probably form four-stranded or tetraplex structures. Thermal denaturation profiles were measured for these polymers at pH8 in the presence of Na+, NH4+, K+, Cs+, Mg2+, Ca2+ and Ba2+. For poly[d(GA)], Na+, NH4+, K+ stabilize the tetraplex to similar extents and the Tm increases with increasing ionic strength. In con...

1. Double-barrelled ion-sensitive micro-electrodes were used to measure changes in the intracellular activities of K+, Na+ and Cl(aK, aNa, acl) in glial cells of slices from guinea-pig olfactory cortex during repetitive stimulation of the lateral olfactory tract. 2. Base-line levels of aj , aia and ai1 were about 66, 25 and 6 mm, respectively, for cells with resting potentials higher than -80 m...

Ca2+ currents recorded from Xenopus oocytes expressing only the alpha1C pore-forming subunit of the cardiac Ca2+ channel show Ca2+-dependent inactivation with a single exponential decay. This current-dependent inactivation is not detected for inward Ba2+ currents in external Ba2+. Facilitation of pore opening speeds up the Ca2+-dependent inactivation process and makes evident an initial fast ra...

(-)-[3H]Desmethoxyverapamil ((-)-DMV) binds saturably to homogenates of the osteoblast-like cell lines UMR 106 and ROS 17/2.8 with KD values of 45 and 61 nM and Bmax values of 6.0 and 5 pmol/mg protein, respectively. Binding is stereoselective with (-)-DMV 8-10 times more potent than (+)-DMV. None of the dihydropyridine or benzothiazepine Ca2+ antagonists examined affect (-)-[3H]DMV binding. Mo...