The role of divalent cations in the mechanism of pyrophosphate-activated, template-directed oligoribonucleotide ligation has been investigated. The dependence of the reaction rate on Mg2+ concentration suggests a kinetic scheme in which a Mg2+ ion must bind before ligation can proceed. Mn2+, Ca2+, Sr2+, and Ba2+ can also catalyze the reaction. Although Pb2+ and Zn2+ do not catalyze the reac...

In the title coordination polymer, [Ag2Cl2(C10H8N2)(C18H15P)2] n , the Ag(I) cation is coordinated by a 4,4'-bi-pyridine N atom, a tri-phenyl-phosphane P atom and two Cl(-) anions in a distorted tetra-hedral geometry. The 4,4-bi-pyridine and Cl(-) anions bridge the Ag(I) cations, forming polymeric chains running along [21-1]. In the crystal, weak C-H⋯Cl inter-actions link the polymeric chains i...

as axon guidance cues. Both plexin B1 and plexin B2 are expressed during mouse kidney development. Inbred plexin B2 knockout (PB2 KO) mice die prenatally with defects in olfactory bulb development, neuronal proliferation and neural tube closure (exencephaly). We report here that these PB2 KO mice have defects also in kidney morphogenesis. In PB2 / embryos the kidneys are smaller and the number ...

The influenza virus polymerase is formed by the PB1, PB2 and PA subunits and is required for virus transcription and replication in the nucleus of infected cells. As PB2 is a relevant host-range determinant we expressed a TAP-tagged PB2 in human cells and isolated intracellular complexes. Alpha-importin was identified as a PB2-associated factor by proteomic analyses. To study the relevance of t...

Ion channels are responsible for control of cell function in excitable tissues such as heart and brain and also in organs and tissues traditionally thought to be non- excitable including liver and epithelium. In the present research, the effect of lead (Pb2+) on Ca2+ -dependent action potential and currents was studied in F77 neuronal soma membrane of Helix aspersa. For this purpose, action pot...

A batch adsorption study was applied to investigate the adsorption of Pb2+ ions from aqueous solutionby nanographene (nG).The adsorption percentage of Pb2+ions onto nG samples at different initial pH,contact time (tc), adsorbent dosage (mnG) and temperature (T) were investigated. The results showedthat nG is an excellent adsorbent for Pb2+ions removal from aqueous solutions with an adsorptionpe...

Pb(III) sorption to hydrous amorphous SiO2 was studied as a function of pH and ionic strength using XAS to characterize the sorption products formed. Pb sorption increased with increasing pH and decreasing ionic strength. The XAS data indicated that the mechanism of Pb(II) sorption to the SiO2 surface was pH-dependent. At pH < 4.5, a mononuclear inner-sphere Pb sorption complex with ionic chara...

That's a wrap: The optical and chiroptical properties of an enantiopure multipodal ortho-oligophenylethynylene presenting four chiral sulfoxide groups at the extremes are presented. presence together with alkynes allows coordination carbophilic Ag(I), and/or oxophilic Zn(II) cations, yielding double helical structures in way.

Capillary zone electrophoresis (CZE) is a sensitive and rapid technique for determining traces of inorganic cations in water samples. CZE with indirect UV-diode array detection (CZE-DAD) was utilized to identify several inorganic cations in natural, potable, and wastewater samples. A pH 4.35 background electrolyte system was employed and consisted of 15 mM imidazole, 8 mM malonic acid, 2 mM 18-...

DNA sequences with guanine repeats can form G-quartets that adopt G-quadruplex structures in the presence of specific metal ions. Using circular dichroism (CD) and ultraviolet-visible (UV-Vis) spectroscopy, we determined the spectral characteristics and the overall conformation of a G-quadruplex of PS2.M with an oligonucleotide sequence, d(GTG(3)TAG(3)CG(3)TTG(2)). UV-melting curves demonstrate...