Servicios de análisis de aguas

Con el propósito de fomentar la transferencia de conocimiento hacia el sector productivo local, el CINDECA propone abordar problemáticas no cubiertas por otros medios diseñando soluciones a medida. De esta manera, surgen nuevos Servicios Tecnológicos de Alto Nivel (STAN) que involucran equipamiento, infraestructura y recursos humanos especializados del Centro

Diversity in the structures and ligand binding sites of nematode fatty acid and retinol binding proteins revealed by Na-FAR-1 from Necator americanus

Fatty acid and retinol binding proteins (FARs) comprise a family of unusual α-helix rich lipid binding proteins found exclusively in nematodes. They are secreted into host tissues by parasites of plants, animals and humans. The structure of a FAR protein from the free-living nematode Caenorhabditis elegans is available, but this protein (Ce-FAR-7) is from a subfamily of FARs that does not appear to be important at the host-parasite interface. We have therefore examined Na-FAR-1 from the blood-feeding intestinal parasite of humans, Necator americanus . The three dimensional structure of Na-FAR-1 in its ligand-free and ligand-bound forms, determined by nuclear magnetic resonance spectroscopy (NMR) and X-ray crystallography, respectively, reveals an a-helical fold similar to Ce-FAR-7, but Na-FAR-1 possesses a larger and more complex internal ligand binding cavity and an additional C-terminal a-helix. Titration of apo -Na-FAR-1 with oleic acid, analysed by NMR chemical shift perturbation, reveals that at least four distinct protein:ligand complexes can be formed. Na-FAR-1, and possibly other FARs, may have a wider repertoire for hydrophobic ligand binding, as confirmed here by our finding that a range of neutral and polar lipids co-purify with the bacterial recombinant protein. Finally, we show by immunohistochemistry that Na-FAR-1 is present in adult worms with a tissue distribution indicative of possible roles in nutrient acquisition by the parasite and in reproduction in the male

Resonance assignment of As-p18, a fatty acid binding protein secreted by developing larvae of the parasitic nematode Ascaris suum

As-p18 is produced and secreted by larvae of the parasitic nematode Ascaris suum as they develop within their eggs. The protein is a member of the fatty acid binding protein (FABP) family found in a wide range of eukaryotes, but is distinctive in that it is secreted from the synthesizing cell and has predicted additional structural features not previously seen in other FABPs. As-p18 and similar proteins found only in nematodes have therefore been designated 'nemFABPs'. Sequence-specific 1H, 13C and 15N resonance assignments were established for the 155 amino acid recombinant protein (18.3 kDa) in complex with oleic acid, using a series of three-dimensional triple-resonance heteronuclear NMR experiments. The secondary structure of As-p18 is predicted to be very similar to other FABPs, but the protein has extended loops that have not been observed in other FABPs whose structures have so far been solved.Facultad de Ciencias MédicasInstituto de Investigaciones Bioquímicas de La Plat

Structure and ligand binding of As-p18, an extracellular fatty acid binding protein from the eggs of a parasitic nematode

Intracellular lipid-binding proteins (iLBPs) of the fatty acid-binding protein (FABP) family of animals transport, mainly fatty acids or retinoids, are confined to the cytosol and have highly similar 3D structures. In contrast, nematodes possess fatty acid-binding proteins (nemFABPs) that are secreted into the perivitelline fluid surrounding their developing embryos. We report structures of As-p18, a nemFABP of the large intestinal roundworm Ascaris suum, with ligand bound, determined using X-ray crystallography and nuclear magnetic resonance spectroscopy. In common with other FABPs, As-p18 comprises a ten β-strand barrel capped by two short α-helices, with the carboxylate head group of oleate tethered in the interior of the protein. However, As-p18 exhibits two distinctive longer loops amongst β-strands not previously seen in a FABP. One of these is adjacent to the presumed ligand entry portal, so it may help to target the protein for efficient loading or unloading of ligand. The second, larger loop is at the opposite end of the molecule and has no equivalent in any iLBP structure yet determined. As-p18 preferentially binds a single 18-carbon fatty acid ligand in its central cavity but in an orientation that differs from iLBPs. The unusual structural features of nemFABPs may relate to resourcing of developing embryos of nematodes

Diversity in the structures and ligand-binding sites of nematode fatty acid and retinol-binding proteins revealed by Na-FAR-1 from Necator americanus

Fatty acid and retinol-binding proteins (FARs) comprise a family of unusual a-helix rich lipid-binding proteins found exclusively in nematodes. They are secreted into host tissues by parasites of plants, animals and humans. The structure of a FAR protein from the free-living nematode Caenorhabditis elegans is available, but this protein [C. elegans FAR-7 (Ce-FAR-7)] is from a subfamily of FARs that does not appear to be important at the host/parasite interface. We have therefore examined [Necator americanus FAR-1 (Na-FAR-1)] from the blood-feeding intestinal parasite of humans, N. americanus. The 3D structure of Na-FAR-1 in its ligand-free and ligand-bound forms, determined byNMR(nuclear magnetic resonance) spectroscopy and X-ray crystallography respectively, reveals an a-helical fold similar to Ce-FAR-7, but Na-FAR-1 possesses a larger and more complex internal ligandbinding cavity and an additional C-terminal a-helix. Titration of apo-Na-FAR-1 with oleic acid, analysed by NMR chemical shift perturbation, reveals that at least four distinct protein-ligand complexes can be formed. Na-FAR-1 and possibly other FARs may have a wider repertoire for hydrophobic ligand binding, as confirmed in the present study by our finding that a range of neutral and polar lipids co-purify with the bacterially expressed recombinant protein. Finally, we show by immunohistochemistry that Na-FAR-1 is present in adult worms with a tissue distribution indicative of possible roles in nutrient acquisition by the parasite and in reproduction in the male.Instituto de Investigaciones Bioquímicas de La Plat

Useable diffraction data from a multiple microdomain-containing crystal ofAscaris suumAs-p18 fatty-acid-binding protein using a microfocus beamline

As-p18 is a fatty-acid-binding protein from the parasitic nematode Ascaris suum. Although it exhibits sequence similarity to mammalian intracellular fatty-acid-binding proteins, it contains features that are unique to nematodes. Crystals were obtained, but initial diffraction data analysis revealed that they were composed of a number of `microdomains'. Interpretable data could only be collected using a microfocus beamline with a beam size of 12 × 8 µm

Metabolism of Pharmaceuticals in Plants and Their Associated Microbiota

With the increasing use of wastewater for irrigation of farmland, and thus the potential uptake and translocation of pharmaceuticals and their metabolites in crops, concerns about food safety are growing. After their uptake, plants are able to metabolize drugs to phase I, phase II, and phase III metabolites. Phase I reactions closely resemble those encountered in human drug metabolism, including oxidations, reductions, and hydrolysis. Phase II reactions, in turn, encompass conjugations with glutathione, carbohydrates, malonic acid, and amino acids. In phase III, these conjugates are transported and stored in the vacuole or bound to the cell wall. Pharmaceutical metabolism in plants has been investigated by using different approaches, namely, the use of whole plants grown in soil or hydroponic cultures, the use of plant tissues, and the incubation of specific plant cell suspensions. While studies relying on whole plants require long growth periods and more complex analytical procedures to isolate and detect metabolites, they constitute more realistic scenarios with the ability to determine site-specific metabolism and the translocation within the plant. The advantage of in vitro studies lies in their rapid setup. Recent advances in plant-microbiota investigations have shown that the plant microbiome modulates the response of the plant towards pharmaceuticals. Rhizospheric and endophytic bacteria can directly contribute to pharmaceutical metabolism and influence plant uptake and translocation of pharmaceuticals and their metabolites. Additionally, they can have beneficial properties for the host, contributing to plant health and fitness. This chapter gives an overview of human and plant drug metabolism followed by a comparison of different models used to identify pharmaceutical metabolites and their metabolic pathways in plants. A description of the mechanisms and reactions originating these metabolites is concisely presented. Finally, the role of the microbiome is critically discussed with examples of synergies between plants and their associated microbiota for pharmaceutical degradation.Peer reviewe