Calcium channels are tightly regulated. Voltage-gated calcium channels open only in response to depolarization, while voltage-independent calcium channels usually open only in response to specific intracellular or extracellular ligands. Voltage-independent calcium channels have been described in several invertebrate neurons. One difficulty in understanding the function of the neuronal channels ...

The chemistry of Mg2+ is unique amongst biological cations, and the properties of Mg2+ transport systems reflect this chemistry. Prokaryotes carry three classes of Mg2+ transport systems: CorA, MgtA/B and MgtE. CorA and MgtE are widely distributed in both Eubacteria and Archaea, while the MgtA/B class is found primarily in the Eubacteria. Eukaryotic homologs of CorA, although clearly functional...

The coordination mode to lithium, magnesium, calcium and zinc cations of racemic vs. enantiopure amino acids racetam APIs is analysed its effect on chiral selection critically reviewed. It shown that resolution in the solid state can be obtained via cocrystallization compounds with an achiral inorganic salt coformer, such as LiX (X=Cl, Br, I) or ZnCl2, which favour tetrahedral state. may take f...

A gradual increase in the concentration of Ca2+ from anterior to the posterior region was observed when mono- and divalent cations were estimated in different segments of the epididymis in wall lizard. Na+ and K+ levels increased from anterior to middle segment but declined significantly in the posterior segment. However, no significant difference in the levels of Mg2+ was observed in various s...

A comparative study of the stabilisation of DNA sticky ends by divalent cations was carried out by atomic force microscopy (AFM), electron microscopy and agarose gel electrophoresis. At room temperature, molecules bearing such extremities are immediately oligomerised or circularised by addition of Mg2+or Ca2+. This phenomenon, more clearly detected by AFM, requires the presence of uranyl salt, ...

The structure of Red clover necrotic mosaic virus (RCNMV), an icosahedral plant virus, was resolved to 8.5 A by cryoelectron microscopy. The virion capsid has prominent surface protrusions and subunits with a clearly defined shell and protruding domains. The structures of both the individual capsid protein (CP) subunits and the entire virion capsid are consistent with other species in the Tombu...

9-Aminoacridine (9AA) binds to photosynthetic membranes of unillum inated chloroplasts in low-salt media. The binding was insensitive to the uncouplers of photophosphorylation. The ap­ parent binding constant was 140 j u m . The binding isotherm as a function of 9AA concentration was sigmoid, and approximately 3 mol 9AA/mol chlorophyll was bound at saturating concentrations of 9AA. Addition of ...

cGMP-dependent protein kinase from bovine lung has been purified to homogeneity using 8-(2-aminoethyl)-amino adenosine 3':5'-monophosphate/Sepharose. Conditions for adsorption of holoenzyme to the affinity chromatography media followed by competitive ligand elution with cGMP have been determined. The holoenzyme of 150,000 molecular weight is composed of two 74,000 molecular weight subunits whic...

Reverse electrodialysis (RED) is a membrane-based renewable energy technology that can harvest energy from salinity gradients. The anticipated feed streams are natural river and seawater, both of which contain not only monovalent ions but also divalent ions. However, RED using feed streams containing divalent ions experiences lower power densities because of both uphill transport and increased ...