L-N(omega),N(omega)-dimethylarginine dimethylaminohydrolase-1 (DDAH-1) is a Zn(II)-containing enzyme that, through hydrolysis of side-chain methylated l-arginines, regulates the activity of nitric-oxide synthase. Herein we report the structural and functional properties of the Zn(II)-binding site in DDAH-1 from bovine brain. Activity measurements of the native and metal-free enzyme have reveale...

InrS is a Ni(II)-responsive, CsoR/RcnR-like, DNA-binding transcriptional repressor of the nrsD gene, but the Ni(II) co-ordination sphere of InrS is unlike Ni(II)-RcnR. We show that copper and Zn(II) also bind tightly to InrS and in vitro these ions also impair InrS binding to the nrsD operator-promoter. InrS does not respond to Zn(II) (or copper) in vivo after 48 h, when Zn(II) sensor ZiaR resp...

The rapid and continuous progress in trace analysis of metals is associated with development of several new techniques such as spectrophotometry. Thiosemicarbazones have been used as chromogenic reagents in spectrophotometric determination of metals. In this study the synthesis and characterization of pyridoxal thiosemicarbazone (PDT) and 2-acetyl pyridine thiosemicarbazone (2-APT) using IR, MS...

The chemically crosslinked metal-complexed chitosans were synthesized by using the ion-imprinting method from a chitosan with four metals (Cu(II), Zn(II), Ni(II) and Pb(II)) as templates and glutaraldehyde as a crosslinker. The influences of adsorption conditions, including molar ratios of crosslinker/chitosan and pH changes, were studied. They were used to investigate for comparative adsorptio...

The batch sorption capability of Romanian pine bark for the removal of Cu(II) and Zn(II) ions from diluted aqueous solutions was investigated as a function of initial pH, contact time, and temperature. The metal sorption sequence is Cu > Zn. The experimental data for Cu(II) and Zn(II) ions retention on the tested bark of Pinus sylvestris L. showed a better compliance with the pseudo–second orde...

the feasibility of kaolinite used as a low-cost adsorbent for the removal of pb(ii), zn(ii) and cu(ii) from aqueous solutions was investigated. during the removal process, batch technique was used, and the effects of heavy metal concentration and contact time on adsorption efficiency at ph of 4.5, under a constant temperature of 20?1 ?c were studied. the experimental results were analyzed using...

In the centrosymmetric trinuclear Zn(II)⋯Ca(II)⋯Zn(II) title complex, [CaZn2(CH3COO)6(C12H12N2)2], the Ca(II) ion lies on an inversion centre and is octa-hedrally coordinated by six acetate O atoms. The Zn(II) ion is coordinated by two N atoms from a bidentate di-methyl-bipyridine ligand and three O atoms from acetate ligands bridging to the Ca(II) ion, leading to a distorted square-pyramidal c...

Histone deacetylase 8 (HDAC8) was originally classified as a Zn(II)-dependent deacetylase on the basis of Zn(II)-dependent HDAC8 activity in vitro and illumination of a Zn(II) bound to the active site. However, in vitro measurements demonstrated that HDAC8 has higher activity with a bound Fe(II) than Zn(II), although Fe(II)-HDAC8 rapidly loses activity under aerobic conditions. These data sugge...

The potential of Bread Fruit (artocarpus altilis)Seed Husk (BFSH) as low-cost biosorbent for the removal of Pb (II), Zn (II) and Co (II) ions from aqueous solution was investigated. The adsorbent was characterized by the Fourier Transform InfraRed (FT-IR)spectroscopy, Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The batch methodology was utilized to dete...