using uv-vis spectrophotometic method, the formation constants for interaction of cd2+(aq) andco2+(aq) ions with l-alanine were experimentally studied at ph = 4.1 ± 0.01 (50mm of potassiumhydrogen phthalate buffer), ionic strength of 0.1m potassium nitrate and at 5 differenttemperatures 15,20, 25,30 and 35°c. the optical absorption spectra of mixtures containingconsidered cations and l-alanine ...

transition-metal-substituted  (tms)  polyoxometalates  of  the  general  formula  [siw9m3o39], (where m = first row transition metal), has been synthesized and supported on anatase by sol–gel method under oil-bath condition. the tetrabutylammonium (tba) salts of the keggin-type polyoxotungstates  [siw9m3o39],  (m = vii, crii, mnii,  feii coii  and niii),  proved  to  be  green, reusable,  and  ...

Vitamin K deficiency or administration of vitamin K antagonists results in the biosynthesis of abnormal des-gamma-carboxy forms of the vitamin K-dependent proteins. Monoclonal antibody H-11 binds several vitamin K-dependent proteins at a determinant that includes the first two residues of gamma-carboxyglutamic acid. Antibody H-11 binds fully carboxylated prothrombin and protein C in the presenc...

The viability of living systems depends inextricably on enzymes that catalyze phosphoryl transfer reactions. For many enzymes in this class, including several ribozymes, divalent metal ions serve as obligate cofactors. Understanding how metal ions mediate catalysis requires elucidation of metal ion interactions with both the enzyme and the substrate(s). In the Tetrahymena group I intron, previo...

Metallothioneins are small cysteine-rich proteins coordinating various transition metal ions preferably with the electron configuration d(10). They are ubiquitously present in all phyla, and next to phytochelatins they represent a successful molecular concept for high-capacity metal ion binding. Recent studies showed the incorporation of sulfide ions into the metal-thiolate cluster of metalloth...

The synthesis and characterization of four p-tert-butylcalix[4]arene-hydroxamic acids are reported. The dependence of the metal ion binding, assessed by liquid–liquid extraction of the metal nitrates from water into dichloromethane in individual and competitive experiments, on the ligand structure, is presented. The results showed that those ligands could be successfully used in separation proc...

Many enzymes use metal ions within their active sites to achieve enormous rate acceleration. Understanding how metal ions mediate catalysis requires elucidation of metal ion interactions with both the enzyme and the substrate(s). The three-dimensional arrangement determined by X-ray crystallography provides a powerful starting point for identifying ground state interactions, but only functional...

Transition metal oxide nanomaterials are promising electrodes for alkali-ion batteries owing to their distinct reaction mechanism, abundant active sites and shortened ion diffusion distance. However, detailed conversion reaction processes in terms of the oxidation state evolution and chemical/mechanical stability of the electrodes are still poorly understood. Herein we explore a general synthet...

Calprotectin (CP) is a transition metal-chelating antimicrobial protein of the calcium-binding S100 family that is produced and released by neutrophils. It inhibits the growth of various pathogenic microorganisms by sequestering the transition metal ions manganese and zinc. In this work, we investigate the manganese-binding properties of CP. We demonstrate that the unusual His(4) motif (site 2)...

The structures of human glyoxalase I in complexes with S-(N-hydroxy-N-p-iodophenylcarbamoyl)glutathione (HIPC-GSH) and S-p-nitrobenzyloxycarbonylglutathione (NBC-GSH) have been determined at 2.0 and 1.72 A resolution, respectively. HIPC-GSH is a transition state analogue mimicking the enediolate intermediate that forms along the reaction pathway of glyoxalase I. In the structure, the hydroxycar...