Metals in proteins from sulphate-reducing bacteria: adenylate kinase and ATP sulfurylase. Proteins containing cobalt, zinc, iron (II) ions

A Thesis submitted at the Faculty Science and Technology of the New University of Lisbon for a degree in Doctor of Philosophy in Biochemistry with specialization in Physical Biochemistry

Cobalt-, zinc- and iron-bound forms of adenylate kinase (AK) from the sulfate-reducing bacterium Desulfovibrio gigas: purification, crystallization and preliminary X-ray diffraction analysis

Acta Crystallogr Sect F Struct Biol Cryst Commun. 2009 Sep 1;65(Pt 9):926-9

Zinc Therapy of Neurological Wilson's Disease in a Woman with Two Foetus with Agenesis of the Corpus Callosum

8A>C>86A G:EDGI: A patient diagnosed Wilson’s disease (WD) 22 years previously, successfully treated initially with zinc, developed neuropsychiatric disease after years of irregular therapy. Reassuming zinc therapy was successful. After a normal pregnancy, she had two therapeutic abortions for corpus callosum agenesis, and a missed abortion. We review the genetics, physiopathology, clinics and imagiologic response to zinc therapy, the problems of pregnancy in WD, advising to maintain therapy. A hypothetic cause for fetus brain anomaly would be hypocupremia due to zinc therapy, confronting with two other possibilities, one related to Wilson’s disease in itself, other due to a congenital syndrome of agenesis of the corpus callosum, impossible to diagnose by our available diagnostic methods.

INVESTIGATION OF BIOFILM FORMATION IN COAGULASE-NEGATIVE STAPHYLOCOCCI ISOLATED FROM PLATELET CONCENTRATE BAGS

Platelet Concentrates (PCs) are the blood components with the highest rate of bacterial contamination, and coagulase-negative staphylococci (CoNS) are the most frequently isolated contaminants. This study investigated the biofilm formation of 16 contaminated units out of 691 PCs tested by phenotypic and genotypic methods. Adhesion in Borosilicate Tube (ABT) and Congo Red Agar (CRA) tests were used to assess the presence of biofilm. The presence of icaADC genes was assessed by means of the Polymerase Chain Reaction (PCR) technique. With Vitek(r)2, Staphylococcus haemolyticus was considered the most prevalent CoNS (31.25%). The CRA characterized 43.8% as probable biofilm producers, and for the ABT test, 37.5%. The icaADC genes were identified in seven samples by the PCR. The ABT technique showed 85.7% sensitivity and 100% specificity when compared to the reference method (PCR), and presented strong agreement (k = 0.8). This study shows that species identified as PCs contaminants are considered inhabitants of the normal skin flora and they might become important pathogens. The results also lead to the recommendation of ABT use in laboratory routine for detecting biofilm in CoNS contaminants of PCs.

Crystal structure of the zinc-, cobalt-, and iron-containing adenylate kinase from Desulfovibrio gigas: a novel metal-containing adenylate kinase from Gram-negative bacteria

J Biol Inorg Chem (2011) 16:51–61 DOI 10.1007/s00775-010-0700-8

Production of ellagitannins concentrate by UF-NF from tropical highland blackberries

Dissertation presented to Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa for obtaining the master degree in Membrane Engineering

Amyotrophic Lateral Sclerosis:Mammalian Cell Models,Copper-Zinc Superoxide Dismutaseand Biological Characteristics

"Amyotrophic Lateral Sclerosis (ALS) is the most severe and common adult onset disorder that affects motor neurons in the spinal cord, brainstem and cortex, resulting in progressive weakness and death from respiratory failure within two to five years of symptoms onset(...)

Vitamin A, vitamin E, iron and zinc status in a cohort of HIV-infected mothers and their uninfected infants

Introduction We hypothesized that nutritional deficiency would be common in a cohort of postpartum, human immunodeficiency virus (HIV)-infected women and their infants. Methods Weight and height, as well as blood concentrations of retinol, α-tocopherol, ferritin, hemoglobin, and zinc, were measured in mothers after delivery and in their infants at birth and at 6-12 weeks and six months of age. Retinol and α-tocopherol levels were quantified by high performance liquid chromatography, and zinc levels were measured by atomic absorption spectrophotometry. The maternal body mass index during pregnancy was adjusted for gestational age (adjBMI). Results Among the 97 women 19.6% were underweight. Laboratory abnormalities were most frequently observed for the hemoglobin (46.4%), zinc (41.1%), retinol (12.5%) and ferritin (6.5%) levels. Five percent of the women had mean corpuscular hemoglobin concentrations < 31g/dL. The most common deficiency in the infants was α-tocopherol (81%) at birth; however, only 18.5% of infants had deficient levels at six months of age. Large percentages of infants had zinc (36.8%) and retinol (29.5%) deficiencies at birth; however, these percentages decreased to 17.5% and 18.5%, respectively, by six months of age. No associations between infant micronutrient deficiencies and either the maternal adjBMI category or maternal micronutrient deficiencies were found. Conclusions Micronutrient deficiencies were common in HIV-infected women and their infants. Micronutrient deficiencies were less prevalent in the infants at six months of age. Neither underweight women nor their infants at birth were at increased risk for micronutrient deficiencies.

Field-effect transistors based on Zinc oxide nanoparticles

This work reports the development of field-effect transistors (FETs), whose channel is based on zinc oxide (ZnO) nanoparticles (NPs). Using screen-printing as the primary deposition technique, different inks were developed, where the semiconducting ink is based on a ZnO NPs dispersion in ethyl cellulose (EC). These inks were used to print electrolyte-gated transistors (EGTs) in a staggered-top gate structure on glass substrates, using a lithium-based polymeric electrolyte. In another approach, FETs with a staggered-bottom gate structure on paper were developed using a sol-gel method to functionalize the paper’s surface with ZnO NPs, using zinc acetate dihydrate (ZnC4H6O4·2H2O) and sodium hydroxide (NaOH) as precursors. In this case, the paper itself was used as dielectric. The various layers of the two devices were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), thermogravimetric and differential scanning calorimetric analyses (TG-DSC). Electrochemical impedance spectroscopy (EIS) was used in order to evaluate the electric double-layer (EDL) formation, in the case of the EGTs. The ZnO NPs EGTs present electrical modulation for annealing temperatures equal or superior to 300 ºC and in terms of electrical properties they showed On/Off ratios in the order of 103, saturation mobilities (μSat) of 1.49x10-1 cm2(Vs)-1 and transconductance (gm) of 10-5 S. On the other hand, the ZnO NPs FETs on paper exhibited On/Off ratios in the order of 102, μSat of 4.83x10- 3 cm2(Vs)-1and gm around 10-8 S.

Assessing the role of Piccolo and Bassoon zinc finger domains on synapse vesicle recycling and maintenance

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2013

Non root feeding with two sources of zinc on Coffea arábica L. 'mundo novo'(B.Rodr.) Choussy

A trial was carried out on an eight old coffee plantation with visible zinc problems. The plantation was situated nearly the city of Jaú (22º30'S, 48º30'W). State of São Paulo, Brazil. The soil is classified as medium texture Oxisol of low base saturation (Latossol Vermelho Amarelo - fase arenosa). The pulverization program started in november 1977, followed in march and July 1978 (heavy harvest) and ended in march and July 1979 (light harvest). Is should be mentioned that a well reconized characteristic of arábica coffe is its habit of biennial bearing, a very heavy harvest is most often followed by a light load the next year. The following treatments and amounts of chemicals per cova hole (4 trees) were tested in accordance with a random block design: 1. 1 g of zinc (zinc sulphate, 0.5%) 2. 3 g of nitrogen (urea, 1.3%) 3. 1 g of zinc + 3 g of nitrogen (zinc sulphate 0.5% + urea 1.3%) 4. 0.25 g, 0.50 g, 1.00 g, 2.00 g of zinc plus 0.75 g, 1.50 g, 3.00 g and 6.00 of nitrogen (correspondent to NZN* 15-0-0-5 as 0.75%, 1-5%, 3.0% and 6.0% by v/v). Foliar absorption data were obtained by collecting the 3rd and 4th pairs of the coffee leaves and analysed them for N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn. The main results may be summarized as follows: 1. The maximum calculated yields of clean coffee were obtained by the applications of 5.84 1 of NZN (1.13%) per hectare. 2. The applications of zinc sulphate (0.5%) and urea (1.3%) together or separate did not affected the coffee bean production. 3. The applications of 15.0 1 of NZN per hectare reduced the coffee yields. 4. Leaf damages and burning symptoms were observed by the applications of urea (1.3%) plus zinc sulphate (0.5%) and larger doses than 7.5 1 of NZN per hectare. 5. Leaf tissue analysis show that the concentrations of the elements were affecred by the age of the leaves and by the yields of the coffee trees. 6. The applications of increasing doses of NZN causes an increase in the concentration of zinc, manganese and boron in the leaves and decreased the concentration in calcium and potassium the leaves. 7. The concentration of zinc in the leaves associated with the heavy harvest, in July, was 70.0 ppm.

Angiotensin-converting enzyme inhibition by hydroxamic zinc-binding idrapril in humans.

The new angiotensin-converting enzyme (ACE) inhibitor idrapril acts by binding the catalytically important zinc ion to a hydroxamic group. We investigated its pharmacodynamic and pharmacokinetic properties in 8 healthy men: Increasing doses of 1, 5, and 25 mg idrapril as well as placebo or 5 mg captopril were administered intravenously (i.v.) at 1-week intervals. Six of the subjects received 100 mg idrapril orally (p.o.) last, and two ingested oral placebo as a double-blind control. Blood pressure (BP) and heart rate (HR) remained unchanged. No serious side effects were observed. ACE inhibition in vivo was evaluated by changes in the ratio of specifically measured plasma angiotensin II (AngII) and AngI concentrations determined by high-performance liquid chromatography/radioimmunoassay (HPLC/RIA) techniques. Plasma ACE activity in vitro was estimated by radioenzymatic assay; it was suppressed by > or = 93% at 15 min after injection of 25 mg idrapril or 5 mg captopril and by 96% 2 h after idrapril intake. Mean AngII levels were decreased dose dependently at 15 min after idrapril injections. At the same time, plasma renin activity (PRA) and AngI increased according to the doses. The AngII/AngI ratio was clearly related to plasma idrapril levels (r = -0.88, n = 60). Oral idrapril inhibited ACE maximally at 1-4 h after dosing, when < 7% of initial ACE activity was observed in vitro and in vivo. Idrapril is a safe and efficient ACE inhibitor in human subjects. It is well absorbed orally. Besides having a slightly slower onset of action, idrapril has pharmacodynamic effects comparable to those of captopril.

Divergent functions of three Candida albicans zinc-cluster transcription factors (CTA4, ASG1 and CTF1) complementing pleiotropic drug resistance in Saccharomyces cerevisiae.

One of the mediators of pleiotropic drug resistance in Saccharomyces cerevisiae is the ABC-transporter gene PDR5. This gene is regulated by at least two transcription factors with Zn(2)-Cys(6) finger DNA-binding motifs, Pdr1p and Pdr3p. In this work, we searched for functional homologues of these transcription factors in Candida albicans. A C. albicans gene library was screened in a S. cerevisiae mutant lacking PDR1 and PDR3 and clones resistant to azole antifungals were isolated. From these clones, three genes responsible for azole resistance were identified. These genes (CTA4, ASG1 and CTF1) encode proteins with Zn(2)-Cys(6)-type zinc finger motifs in their N-terminal domains. The C. albicans genes expressed in S. cerevisiae could activate the transcription of a PDR5-lacZ reporter system and this reporter activity was PDRE-dependent. They could also confer resistance to azoles in a S. cerevisiae strain lacking PDR1, PDR3 and PDR5, suggesting that CTA4-, ASG1- and CTF1-dependent azole resistance can be caused by genes other than PDR5 in S. cerevisiae. Deletion of CTA4, ASG1 and CTF1 in C. albicans had no effect on fluconazole susceptibility and did not alter the expression of the ABC-transporter genes CDR1 and CDR2 or the major facilitator gene MDR1, which encode multidrug transporters known as mediators of azole resistance in C. albicans. However, additional phenotypic screening tests on the C. albicans mutants revealed that the presence of ASG1 was necessary to sustain growth on non-fermentative carbon sources (sodium acetate, acetic acid, ethanol). In conclusion, C. albicans possesses functional homologues of the S. cerevisiae Pdr1p and Pdr3p transcription factors; however, their properties in C. albicans have been rewired to other functions.

Hydrocarbon biomarkers in the Topla-Mezica zinc-lead deposits, northern Karavanke/Drau Range, Slovenia: Paleoenvironment at the site of ore formation

The Mississippi Valley-type zinc and lead deposits at Topla (250,150 metric tons (t) of ore grading 1.0 wt % Zn and 3.3 wt % Pb) and Mezica (19 million metric tons (Mt) of ore grading 5.3 wt % Pb and 2.7 wt % Zn) occur within the Middle to Upper Triassic platform carbonate rocks of the northern Karavanke/Drau Range geotectonic units of the Eastern Alps, Slovenia. The ore and host rocks of these deposits have been investigated by a combination of inorganic and organic geochemical methods to determine major, trace, and rare earth element (REE) concentrations, hydrocarbon distribution, and stable isotope ratios of carbonates, kerogen, extractable organic matter, and individual hydrocarbons. These data combined with sedimentological evidence provide insight into the paleoenvironmental conditions at the site of ore formation. The carbonate isotope composition, the REE patterns, and the distribution of hydrocarbon biomarkers (normal alkanes and steranes) suggest a marine depositional environment. At Topla, a relatively high concentration of redox sensitive trace elements (V, Mo, U) in the host dolostones and REE patterns parallel to that of the North American shale composite suggest that sediments were deposited in a reducing environment. Anoxic conditions enhanced the preservation of organic matter and resulted in relatively higher total organic carbon contents (up to 0.4 wt %). The isotopic composition of the kerogen (delta C-13(kerogon) = -29.4 to -25.0 parts per thousand, delta N-15(kerogen) = -.13.6 to 6.8 parts per thousand) suggests that marine algae and/or bacteria were the main source of organic carbon with a very minor contribution from detrital continental plants and a varying degree of alteration. Extractable organic matter from Topla ore is generally depleted in C-13 compared to the associated kerogen, which is consistent with an indigenous source of the bitumens. The mineralization correlates with delta N-15(kerogen) values around 0 per mil, C-13 depleted kerogen, C-13 enriched n-heptadecane, and relatively high concentrations of bacteria] hydrocarbon biomarkers, indicating a high cyanobacterial biomass at the site of ore formation. Abundant dissimilatory sulfate-reducing bacteria, feeding on the cyanobacterial remains, led to accumulation of biogenic H2S in the pore water of the sediments. This biogenic H2S was mainly incorporated into sedimentary organic matter and diagenetic pyrite. Higher bacterial activity at the ore site also is indicated by specific concentration ratios of hydrocarbons, which are roughly correlated with total Pb plus Zn contents. This correlation is consistent with mixing of hydrothermal metal-rich, fluids and local bacteriogenic sulfide sulfur. The new geochemical data provide supporting evidence that Topla is a low-temperature Mississippi Valley-type deposit formed in an anoxic supratidal saline to hypersaline environment. A laminated cyanobacterial mat, with abundant sulfate-reducing bacteria was the main site of sulfate reduction.

Zinc Sulphate in the Treatment of Cutaneous Leishmaniasis: an in Vitro and Animal Study

This study was designed to evaluate the effectiveness of zinc sulphate both in vitro and in an animal model against both strains of old world cutaneous leishmaniasis. The in vitro sensitivities of promastigotes and axenic amastigotes of both Leishmania major and L. tropica to zinc sulphate was determined, the LD50 calculated and compared to the standard treatment for cutaneous leishmaniasis pentavalent antimony compounds. The results show that the two forms of both strains were sensitive to zinc sulphate and their respective LD50 were lower compared to the pentavalent antimony compound. Furthermore the sensitivities of the forms of both strains were tested using a simple slide method and compared to results of the standard method. To confirm this result, zinc sulphate was administered orally to mice infected with cutaneous leishmaniasis both therapeutically and prophylactically. Results showed that oral zinc sulphate was effective in both treatment and prophylaxis for cutaneous leishmaniasis. These results encourage the use of oral zinc sulphate in the treatment of cutaneous leishmaniasis clinically.