BioMetals
The effects of trivalent metal ions such as lanthanoid (La , Ce, Nd , Sm , Gd , Er , Yb , Lu ) and Al ions on the morphological change and proliferation of B16 melanoma cells in culture are discussed. These metal ions induced morphological transformations and decreased growth rates at doses of 1 mM. B16 melanoma cells treated with La , Ce , Nd , Sm , and Gd showed polyhedrical spreading. Elongation...
Fe(II) oxidation reaction was carried out using an acidophilic microorganism, Thiobacillus ferrooxidans. Four different parameters such as pH, Fe(II), Fe(III) and biomass concentration were studied. The oxida-tion reaction follows a pseudo first order rate equation. Apparent reaction rate constants were calculated. Unified rate equation was developed using the four parameters. Along with oxidation,...
The recovery of gold from gold-thiourea solutions using various types of waste biomass was investigated. All organisms tested, namely, Saccharomyces cerevisiae, Spirulina platensis and Streptomyces erythraeus removed gold rapidly from gold–thiourea solutions. The process of gold accumulation was pH-dependent for Saccharomyces ceresvisiae and Streptomyces erythraeus and independent of pH in the case...
The inhibitory effect of bovine lactoferrin (BLf) saturated with ferric, manganese or zinc ions, on the infection of Vero cells by human herpes simplex virus type 1 (HSV1) and 2 (HSV2) was investigated. Viral infectivity determined by intracellular antigen synthesis and plaque formation was efficiently inhibited by metal saturated lactoferrins in a dose-dependent manner. Effective BLf concentrations...
Several studies were undertaken to compare four magnetic resonance imaging (MRI) contrast media (CM) as regards acute haemodynamic effects in rats and to investigate the mechanisms involved. (1) Normotensive rats received a rapid bolus intravenous injection of 0.5 mmol kg of each CM. The effects of Gd-DOTA, Gd-HP-DO3A, Gd-DTPA and Gd-DTPA-BMA on blood pressure (BP) were compared. (2) The haemo-dynamic...
The mechanism of ascorbate oxidation by metal-binding proteins (ceruloplasmin, albumin and transferrin) was investigated in vitro and in isolated plasma by the measurement of the ascorbyl free radicals (AFR) by electron spin resonance (ESR). In plasma of 13 healthy volunteers, a spontaneous and variable pro-duction of AFR was detected, which was increased by a 10 M ascorbate overloading; however,...
Cadmium induced lipid peroxidation (LPO) and the activity of antioxidantenzymes after the administration of a single dose of CdCl 2 (0.4 mg kg body wt, ip) was studied in rat erythrocytes.Cd intoxication increased erythrocyte LPO along with a decrease insuperoxide dismutase (SOD) up to three days of Cd treatment. Thedecrease in erythrocyte catalase (CAT) activity was marked within9 h of Cd intoxication...
The particulate methane monooxygenase (pMMO) from Methylosinus trichosporium OB3b was partiallypurified and characterized by measuring the effects of reducing agents and additives, and the stability ofpMMO was studied. Duroquinol was a suitable reducing agent, and pMMO was stabilized by bovine serumalbumin (BSA). Among the additivies, the copper (II) ion stimulated pMMO at low concentration andinhibited...
Pyridoxal isonicotinoyl hydrazone (PIH), salicylaldehydebenzoyl hydrazone (SBH), and their analogschelate iron(III) and show promise asorally effective drugs for treating diseases of iron overload. Theirbiological activity isrelated to their lipophilicity, as measured by their partition coefficients P betweenn-octanoland water. However, the method of calculating log P described in an article in this...
This work was undertaken to analyse the effects of acutecadmium administration on the pulsatile patternof prolactin release, in adult male rats.For this purpose, animals were cannulated 40 h before the experi-mentto allow a continuousblood withdrawal. Two hours after the administration of one dose of cadmiumchloride (4.5 mg kg1 ), the pulsatile pattern of prolactin, during three hours, was studied...
The metal ion requirement for both enzymatic activitiesof the bifunctional UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosaminekinase (E.C. 5.1.3.14/ 2.7.1.60), the key enzyme of N-acetylneuraminic acidbiosynthesis in ratliver, was investigated. UDP-N-acetylglucosamine 2-epimerase was active inimida-zole/HCl buffer in the complete absence of any metal ion. 200 mM Na + , K + , Rb + and Cs +activated...
A novel 1,3,5-triamino-myo-inositol derivative ispresented as a readily available scaffold for the design oftripodal siderophore mimetics.Based on this scaffold, various hexadentate catecholate-type siderophoreanalogs weresynthesized by attaching the catechols to the inositol scaffold via spacer units of differentstruc-tureand length. The potential to tune the polarity of the inositol containing siderophoreanalogs...
The chemotherapeutic agent, bleomycin, forms a 1:1complex with both Fe(III) and Fe(II). The rate offerric ion transfer from bleomycin toapotransferrin is rather slow. However, when ascorbate was added toFe(III)-bleomycin priorto exposure to apotransferrin, the transfer rate was markedly increased. Ascorbatereadilyreduces Fe(III)-bleomycin to Fe(II)-bleomycin. A second order rate constant of 2.4 mM...
Lead is a highly toxic metal, the main source of which iscontamination from combustion of unleaded petrol.The aims of this work were todetect the degree of lead exposure in a large sample of children; determinetherelationship between blood lead levels (BPb) and age, sex, habitat and season of the year;andcorrelate BPb with zinc protoporphyrin (ZPP) values. A cross-sectional study wascarried out. Blood...
Copper deficiency has been reported to be associated withdecreased cytochrome c oxidase activity, whichin turn may be responsible for theobserved mitochondrial impairment and cardiac failure. We isolatedmito-chondriafrom hearts of copper-deficient rats: cytochrome c oxidase activity was found to be lowerthan incopper-adequate mitochondria. The residual activity paralleled coppercontent of mitochondria...
Cellular resistance of cisplatin is related to variousfactors such as membrane transformations, changes incellular transport systems, andan increased efflux of cisplatin by the tumor cells. Deficiencies of one ormoretrace metals can affect normal physiological functions, leading to altered enzymaticactivities and areduction in immune responses. This in vitro investigation was undertaken tostudy and...
Hypotransferrinemia is a genetic defect in mice resultingin 1% of normal plasma transferrin (Tf) concen-trations;heterozygotes for thismutation (+/hpx) have low circulating Tf concentrations. These mice providea unique opportunity toexamine the developmental pattern and response of Tf to iron-deficient diets, andfurthermore,to address the controversial role of Tf in Mn transport. Twenty-three weanling...
The effects of cadmium on adrenocorticotropin hormone(ACTH) secretion are controversial and seem todepend on the dose and duration ofthe exposure to the metal. This work was undertaken to analyze theeffects of acutecadmium administration on the episodic pattern of ACTH release in adult male rats. Forthispurpose, animals were cannulated 40 h before the experiment to allow a continuousblood withdrawal...
Escherichia coli will reduce selenite (SeO 3 2- ) andselenate (SeO 4 2- ) to elemental selenium Se 0 . Seleniumwill also become incorporated intoproteins as part of the amino acids selenocysteine or selenomethionine.The reaction of selenitewith glutathione produces selenodiglutathione (GS-Se-GS). Selenodiglutathioneand itssubsequent reduction to glutathioselenol (GS-SeH) are likely the key intermediatesin...
Calmodulin is an important second messenger protein which is involved in a large variety of cellular path-ways.Calmodulin is sensitive to fluctuations in the intracellular Ca levels and is activated by the bindingof four Ca ions. In spite of the important role it plays in signal transduction pathways, it shows a surpris-inglybroad specificity for binding metal ions. Using 15N-Gly biosynthetically-labelled...