Topología del complejo multienzimático ácido graso sintetasa del insecto Ceratitis capitata

Tesis - Universidad Complutense de Madrid, 1982.Depto. de Bioquímica y Biología MolecularFac. de Ciencias QuímicasTRUEProQuestpu

Movimiento de escape

El presente trabajo de final de Grado es el resultado de una investigación en la que se combinan los diferentes procesos creativos que hemos desarrollado en los dos últimos años de carrera. El proyecto ¿Movimiento de Escape¿ se ha llevado a cabo mediante la ¿mixtura¿ entre procesos formales pictóricos y procesos tecnológicos y digitales. Un trabajo donde forzamos la comunicación gráfica (diseño) y la traducimos a un lenguaje abstracto, y en el que, de forma recíproca, sometemos la pintura a planteamientos de maquetación y composición comunicativa. Un ir y venir entre lo digital y lo pictórico en tierra de nadie, un proyecto de diseño especulativo que, mediante un diálogo cartográfico de huellas migratorias, aborda una problemática que evidencia nuestro fracaso colectivo como sociedad desarrollada; un lenguaje que analiza la ubicación de los asentamientos de desplazados internos y refugiados, y los recorridos realizados por estos en su huida de guerras civiles y de violencia extrema en sus lugares de origen. Se trata de un TFG/Proyecto práctico que juega con distintas maneras de abordar la imagen; la de la tradición (pintura, representación, imagen física,...) y la contemporánea (imagen digital), a partir del valor del signo y la marca, su dexcontextualización, y de tratamientos informáticos (diseño, composición, impresión, corte...).This final degree paper is the result of a research that combines the different creative processes I have developed in the last two years of my degree. The project ¿Movement to Escape¿ has been carried out through the ¿mixture¿ of pictorial formal processes together with technological and digital processes. A work graphic communication (design) is pushed, translating it into an abstract language and, reciprocally, the painting is submmited to layout and communicative composition approaches. A back and forth movement between the digital and the pictorial world in no man¿s land, a speculative design project that, through a cartographic dialogue of migratory footprints, addresses a problem that demonstrates our collective failure as a developed society. A dialogue that maps the location of the settlements of internally moved people and refugees, and the journeys made by them in their escape from civil wars and extreme violence in their places of origin. It is a FDP / Practical project that plays with different ways of approaching the image, from both a traditional (painting, representation, physical image, ...) and a contemporary (digital image) perspective, based on the value of the sign and the mark, its dexcontextualization, and computer processing (design, composition, printing, cutting ...). Keywords: Design, paint, image, signange, poster, intervention, markUrban Oñaderra, JL. (2018). Movimiento de escape. http://hdl.handle.net/10251/111889TFG

Topología del complejo multienzimático ácido graso sintetasa del insecto Ceratitis capitata

Tesis - Universidad Complutense de Madrid, 1982.Depto. de Bioquímica y Biología MolecularFac. de Ciencias QuímicasTRUEProQuestpu

Sea anemone actinoporins: The transition from a folded soluble state to a functionally active membrane-bound oligomeric pore

Actinoporins are a family of 20-kDa, basic proteins isolated from sea anemones, whose activity is inhibited by preincubation with sphingomyelin. They are produced in monomeric soluble form but, when binding to the plasma membrane, they oligomerize to produce functional pores which result in cell lysis. Equinatoxin II (EqtII) from Actinia equina and Sticholysin II (StnII) from Stichodactyla helianthus are the actinoporins that have been studied in more detail. Both proteins display a beta-sandwich fold composed of 10 beta-strands flanked on each side by two short alpha-helices. Twodimensional crystallization on lipid monolayers has allowed the determination of low-resolution models of tetrameric structures distinct from the pore. However, the actual structure of the pore is not known yet. Wild-type EqtII and StnII, as well as a nice collection of natural and artificially made variants of both proteins, have been produced in Escherichia coli and purified. Their characterization has allowed the proposal of a model for the mechanism of pore formation. Four regions of the actinoporins structure seem to play an important role. First, a phosphocholine-binding site and a cluster of exposed aromatic residues, together with a basic region, would be involved in the initial interaction with the membrane, whereas the amphipathic N-terminal region would be essential for oligomerization and pore formation. Accordingly, the model states that pore formation would proceed in at least four steps: Monomer binding to the membrane interface, assembly of four monomers, and at least two distinct conformational changes driving to the final formation of the functional pore

Minimized natural versions of fungal ribotoxins show improved active site plasticity

Fungal ribotoxins are highly specific extracellular RNases which cleave a single phosphodiester bond at the ribosomal sarcin-ricin loop, inhibiting protein biosynthesis by interfering with elongation factors. Most ribotoxins show high degree of conservation, with similar sizes and amino acid sequence identities above 85%. Only two exceptions are known: Hirsutellin A and anisoplin, produced by the entomopathogenic fungi Hirsutella thompsonii and Metarhizium anisopliae, respectively. Both proteins are similar but smaller than the other known ribotoxins (130 vs 150 amino acids), displaying only about 25% sequence identity with them. They can be considered minimized natural versions of their larger counterparts, best represented by α-sarcin. The conserved α-sarcin active site residue Tyr48 has been replaced by the geometrically equivalent Asp, present in the minimized ribotoxins, to produce and characterize the corresponding mutant. As a control, the inverse anisoplin mutant (D43Y) has been also studied. The results show how the smaller versions of ribotoxins represent an optimum compromise among conformational freedom, stability, specificity, and active-site plasticity which allow these toxic proteins to accommodate the characteristic abilities of ribotoxins into a shorter amino acid sequence and more stable structure of intermediate size between that of other nontoxic fungal RNases and previously known larger ribotoxins

Herramientas de comunicación en el aprendizaje de la Bioquímica

Sección Deptal. de Bioquímica y Biología Molecular (Biológicas)Depto. de Bioquímica y Biología MolecularFac. de Ciencias BiológicasFac. de Ciencias QuímicasFALSEsubmitte

Effects of immobilized VEGF on endothelial progenitor cells cultured on silicon substituted and nanocrystalline hydroxyapatites

Vascular endothelial growth factor (VEGF) plays an essential role in angiogenesis and vascular homeostasis. Endothelial progenitor cells (EPCs) are primitive bone marrow cells participating in neovascularization and revascularization processes, which also promote bone regeneration. Synthetic hydroxyapatite (HA) has been widely used in bone repair and implant coatings. In HA-based materials, small levels of ionic substitution by silicon (Si) have significant effects on osteoclastic and osteoblastic responses. Moreover, nanocrystalline hydroxyapatites (nano-HA) display enhanced bioreactivity and beneficial effects in bone formation. In this work, the angiogenic potential of VEGF-121 adsorbed on crystalline and nanocrystalline HAs with different Si proportion is evaluated with endothelial-like cells derived from EPCs cultured on nano-HA, nano-SiHA0.25, nano-SiHA0.4, HA, SiHA0.25 and SiHA0.4 disks. The Si amount incorporated for x ¼ 0.25 is enough to yield changes in the textural parameters and surface charge without decomposing the HA phase. Si substitution for x ¼ 0.4 does not result in pure Si-substituted apatites. Si probably remains at the grain boundaries as amorphous silica in nano-SiHA0.4 and SiHA0.4 is decomposed in a-TCP and HA after 1150 �C treatment. Immobilized VEGF on nano-HA, nano-SiHA0.25, nano-SiHA0.4, HA, SiHA0.25 and SiHA0.4 maintains its function exerting a local regulation of the cell response. The crystallite size and topography of nanocrystalline HAs could produce insufficient and weak contacts with endothelial-like cells triggering anoikis. Concerning Si proportion, the best results are obtained with SiHA0.25/VEGF and nano- SiHA0.25/VEGF disks. All these results suggest the potential utility of SiHA0.25/VEGF and nano-SiHA0.25/VEGF for bone repair and tissue engineering by promoting angiogenesis

Involvement of loops 2 and 3 of alpha-sarcin on its ribotoxic activity

Ribotoxins are a family of fungal ribosome-inactivating proteins displaying highly specific ribonucleolytic activity against the sarcin/ricin loop (SRL) of the larger rRNA, with a-sarcin as its best-characterized member. Their toxicity arises from the combination of this activity with their ability to cross cell membranes. The involvement of a-sarcin's loops 2 and 3 in SRL and ribosomal proteins recognition, as well as in the ribotoxin-lipid interactions involving cell penetration, has been suggested some time ago. In the work presented now different mutants have been prepared in order to study the role of these loops in their ribonucleolytic and lipid-interacting properties. The results obtained confirm that loop 3 residues Lys 111, 112, and 114 are key actors of the specific recognition of the SRL. In addition, it is also shown that Lys 114 and Tyr 48 conform a network of interactions which is essential for the catalysis. Lipid-interaction studies show that this Lys-rich region is indeed involved in the phospholipids recognition needed to cross cell membranes. Loop 2 is shown to be responsible for the conformational change which exposes the region establishing hydrophobic interactions with the membrane inner leaflets and eases penetration of ribotoxins target cells

Early in vitro response of macrophages and T lymphocytes to nanocrystalline hydroxyapatites

Hypothesis: Synthetic hydroxyapatite (HA) and Si substituted hydroxyapatite (SiHA) are calcium phosphate ceramics currently used in the field of dentistry and orthopaedic surgery. The preparation of both biomaterials as polycrystalline solid pieces or grains formed by nanocrystallites has awakened a great interest to enhance the bioactive behavior due to the microstructural defects and the higher surface area. The study of the macrophage and lymphocyte behavior in contact with nanocrystalline HA and SiHA will allow to elucidate the immune response which conditions the success or rejection of these biomaterials. Experiments: HA and SiHA granules (with sizes of tens of microns) have been prepared by controlled aqueous precipitation avoiding subsequent high temperature sintering. HA and SiHA granules were constituted by crystallites smaller than 50 nm. The effects of both nanocrystalline materials on immune system have been evaluated with macrophages (main components of innate immune system) and T lymphocytes (specific cells of adaptive response) after short-term culture as in vitro models of the early immune response. Findings: Significant decreases of macrophage proliferation and phagocytic activity, increased production of inflammatory cytokines (IL-6, TNF-a) and T lymphocyte apoptosis, were induced by these nanocrystalline ceramics suggesting that, after in vivo implantation, they induce significant effects on immune responses, including an early activation of the innate immune system. (C) 2013 Elsevier Inc. All rights reserved

Response of osteoblasts and preosteoblasts to calcium deficient and Sisubstituted hydroxyapatites treated at different temperatures

tHydroxyapatite (HA) is a calcium phosphate bioceramic widely used for bone grafting and augmenta-tion purposes. The biological response of HA can be improved through chemical and microstructuralmodifications, as well as by manufacturing it as macroporous implants. In the present study, calciumdeficient hydroxyapatite (CDHA) and Si substituted hydroxyapatite (SiHA) macroporous scaffolds havebeen prepared by robocasting. In order to obtain different microstructural properties, the scaffolds havebeen treated at 700◦C and 1250◦C. The scaffolds have been characterized and tested as supports forboth osteoblast growth and pre-osteoblast differentiation, as fundamental requisite for their potentialuse in bone tissue engineering. Morphology, viability, adhesion, proliferation, cell cycle, apoptosis, intra-cellular content of reactive oxygen species and interleukin-6 production were evaluated after contactof osteoblasts-like cells with CDHA and SiHA materials. An adequate interaction of osteoblasts-like cellsand preosteoblasts-like cells with all these scaffolds was observed. However, the higher bone cell pro-liferation and differentiation on CDHA and SiHA scaffolds treated at 1250◦C and the lower adsorptionof albumin and fibrinogen on these materials in comparison to those treated at 700◦C, suggest a bettertissue response to CDHA and SiHA materials treated at high temperature