1. Intracellular recordings were made from the myoepithelial cells of the proventriculus of the marine polychaete worm Syllis spongiphila. Over-shooting responses were elicited either by carbamylcholine added to the bathing medium or by directly applied intracellular current pulses. 2. In control artificial sea water (ASW) directly applied current pulses elicited regenerative responses of 68-11...

Generation of factor VIII cofactor activity requires divalent metal ions such as Ca2+ or Mn2+. Evaluation of cofactor reconstitution from isolated factor VIIIa subunits revealed the presence of a functional Ca2+ binding site within the A1 subunit. Isothermal titration calorimetry demonstrated at least two Ca2+ binding sites of similar affinity (K(d) = 0.74 microm) within the A1 subunit. Mutagen...

The Treponema pallidum tro operon encodes an ABC transporter (TroABCD), a transcriptional repressor (TroR), and the essential glycolytic enzyme phosphoglycerate mutase (Gpm). The apparently discordant observations that the solute binding protein (TroA) binds Zn2+, whereas DNA binding by TroR in vitro is Mn2+-dependent, have generated uncertainty regarding the identities of the ligand(s) and co-...

Cells of Leptothrix discophora SS1 released Mn2+-oxidizing factors into the medium during growth in batch culture. Manganese was optimally oxidized when the medium was buffered with HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) at pH 7.5. Manganese-oxidizing activity in the culture medium in which this strain had been grown previously was sensitive to heat, phosphate, Tris, NaN3, ...

Human umbilical-vein endothelial cells stimulated with thrombin or histamine show an increase in [Ca2+]i (cytoplasmic free calcium concn.) that is maintained well above the basal pre-stimulated value as long as agonist and a source of extracellular Ca2+ are present. These results provide circumstantial evidence that agonists stimulate influx of Ca2+ across the plasma membrane and into the cytop...

We used solid-condition processes to make a sequence of radiation-adjustable phosphors Eu2+/Mn2+ co-doped Ca9La(PO4)7 (shortened as CaLa:EM), which show consistently variable hue from green yellow and red via an efficient resonance-form energy transition well the strength radiations may be controllable through altering Mn2+concentration. examined (Eu2+®Mn2+) for CaLa:EM. It is proved resonant k...

The binding of Ca2+, Zn2+, Tb3+, and Mn2+ to metal-free bovine alpha-lactalbumin (apo-BLA) was studied by both analytical gel filtration using isotopic metal ions and by fluorescence titration. In the absence of other metal ions, Ca2+ binds at a single site on apo-BLA. The pH dependence of pKa for calcium binding indicates that carboxylate groups of aspartic and/or glutamic residues are coordin...

Layered vanadium oxides are promising cathode materials for zinc-ion batteries (ZIBs) owing to their high capacity, but the sluggish electron/ion migration kinetics and structural collapse/dissolution severely limit Zn2+-storage performance. Herein, poly(3,4-ethylenedioxythiophene) coated Mn2+-intercalated with rich oxygen vacancies ([email protected]) prepared as cathodes ZIBs. The PEDOT coati...

Horseradish peroxidase has been shown to catalyze the oxidation of veratryl alcohol (3,4-dimethoxybenzyl alcohol) and benzyl alcohol to the respective aldehydes in the presence of reduced glutathione, MnC12, and an organic acid metal chelator such as lactate. The oxidation is most likely the result of hydrogen abstraction from the benzylic carbon of the substrate alcohol leading to eventual dis...