Marcel Proust lector de la Recherche

Fil: Moran, Julio César. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

La visión ficcionalizada de pintores y obras pictóricas en la Recherche

Fil: Solas, Silvia Angélica. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Les chaînes de références dans des corpus textuels trilingues : Critères et finalité de la recherche

En la obra Stylistique comparée du français et de l?anglais, Vinay y Darbelnet señalan el valor de la traducción como disciplina auxiliar de la Lingüística (1977: 25). Sin entrar en el debate sobre el alcance de las nociones de traducción y transcodificación, se entiende que en toda situación de lenguas en contactos, como es el caso de la traducción, el universal de interferencia influye sobre los mecanismos discursivos relacionados con la memoria, de manera tal que la producción de un texto traducido sin visibilidad de interferencia supone esfuerzos especiales por parte del traductor (Toury, 2004: 345). En el marco de esta problemática, nuestro estudio respecto de las cadenas referenciales (CR) en corpora trilingües se fundamenta en los trabajos de Ariel (1990) y, especialmente de Schnedecker (1997, 2005), en cuanto a las expresiones referenciales que mantienen la cohesión del texto y sus relaciones con la accesibilidad al referente. Los resultados de este estudio descriptivo y contrastivo a partir de un corpus de textos trilingües podrán contribuir al conocimiento del macroproceso de traducción y, por consiguiente, a la formación de traductores. Asimismo, esta presentación se inscribe en el marco de la Traductología y aspira a ser un aporte a otras disciplinas, especialmente a la Lingüística, en una relación de reciprocidad (García, 2012: 78)

Les chaînes de références dans des corpus textuels trilingues : Critères et finalité de la recherche

En la obra Stylistique comparée du français et de l?anglais, Vinay y Darbelnet señalan el valor de la traducción como disciplina auxiliar de la Lingüística (1977: 25). Sin entrar en el debate sobre el alcance de las nociones de traducción y transcodificación, se entiende que en toda situación de lenguas en contactos, como es el caso de la traducción, el universal de interferencia influye sobre los mecanismos discursivos relacionados con la memoria, de manera tal que la producción de un texto traducido sin visibilidad de interferencia supone esfuerzos especiales por parte del traductor (Toury, 2004: 345). En el marco de esta problemática, nuestro estudio respecto de las cadenas referenciales (CR) en corpora trilingües se fundamenta en los trabajos de Ariel (1990) y, especialmente de Schnedecker (1997, 2005), en cuanto a las expresiones referenciales que mantienen la cohesión del texto y sus relaciones con la accesibilidad al referente. Los resultados de este estudio descriptivo y contrastivo a partir de un corpus de textos trilingües podrán contribuir al conocimiento del macroproceso de traducción y, por consiguiente, a la formación de traductores. Asimismo, esta presentación se inscribe en el marco de la Traductología y aspira a ser un aporte a otras disciplinas, especialmente a la Lingüística, en una relación de reciprocidad (García, 2012: 78)

Anne Simon, Proust et le réel retrouvé. Le sensible et son expression dans À la recherche du temps perdu. París, Presses Universitaires de France, noviembre de 2000, p. 284.

Fil: Solas, Silvia. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Etude d'une méthode de recherche du mínimum dans une espace A N dimensions sans contrainte + quelques considerations sur deux méthodes de minimisation le long d'une direction dans l'espace

Les méthodes d'optimisation statiques(c'est-a-dire des systemes dont les parametres n'.évoluent pas avec le temps) peuvent se diviser en deux grandes classes : les méthodes directes et les méthodes indirectes. Les premieres ocalisent le vecteur optimum par des mouvements tratégiques dans l'espace correspondant. Elles nécessitent la connaissance de la valeur de la fonction critere a chaque point, mais non la forme algébrique, ni ses dérivées.

Evidence for a structural motif in toxins and interleukin-2 that may be responsible for binding to endothelial cells and initiating vascular leak syndrome

The dose-limiting toxicity of interleukin-2 (IL-2) and immunotoxin (IT) therapy in humans is vascular leak syndrome (VLS). VLS has a complex etiology involving damage to vascular endothelial cells (ECs), extravasation of fluids and proteins, interstitial edema, and organ failure. IL-2 and ITs prepared with the catalytic A chain of the plant toxin, ricin (RTA), and other toxins, damage human ECs in vitro and in vivo. Damage to ECs may initiate VLS; if this damage could be avoided without losing the efficacy of ITs or IL-2, larger doses could be administered. In this paper, we provide evidence that a three amino acid sequence motif, (x)D(y), in toxins and IL-2 damages ECs. Thus, when peptides from RTA or IL-2 containing this sequence motif are coupled to mouse IgG, they bind to and damage ECs both in vitro and, in the case of RTA, in vivo. In contrast, the same peptides with a deleted or mutated sequence do not. Furthermore, the peptide from RTA attached to mouse IgG can block the binding of intact RTA to ECs in vitro and vice versa. In addition, RTA, a fragment of Pseudomonas exotoxin A (PE38-lys), and fibronectin also block the binding of the mouse IgG-RTA peptide to ECs, suggesting that an (x)D(y) motif is exposed on all three molecules. Our results suggest that deletions or mutations in this sequence or the use of nondamaging blocking peptides may increase the therapeutic index of both IL-2, as well as ITs prepared with a variety of plant or bacterial toxins.

Light-activated rhodopsin induces structural binding motif in G protein α subunit

A large superfamily of transmembrane receptors control cellular responses to diverse extracellular signals by catalyzing activation of specific types of heterotrimeric GTP-binding proteins. How these receptors recognize and promote nucleotide exchange on G protein α subunits to initiate signal amplification is unknown. The three-dimensional structure of the transducin (Gt) α subunit C-terminal undecapeptide Gtα(340–350) IKENLKDCGLF was determined by transferred nuclear Overhauser effect spectroscopy while it was bound to photoexcited rhodopsin. Light activation of rhodopsin causes a dramatic shift from a disordered conformation of Gtα(340–350) to a binding motif with a helical turn followed by an open reverse turn centered at Gly-348, a helix-terminating C capping motif of an αL type. Docking of the NMR structure to the GDP-bound x-ray structure of Gt reveals that photoexcited rhodopsin promotes the formation of a continuous helix over residues 325–346 terminated by the C-terminal helical cap with a unique cluster of crucial hydrophobic side chains. A molecular mechanism by which activated receptors can control G proteins through reversible conformational changes at the receptor–G protein interface is demonstrated.

Purification and characterization of sortase, the transpeptidase that cleaves surface proteins of Staphylococcus aureus at the LPXTG motif

Surface proteins of Staphylococcus aureus are linked to the bacterial cell wall by sortase, an enzyme that cleaves polypeptides at the threonine of the LPXTG motif. Surface proteins can be released from staphylococci by treatment with hydroxylamine, resulting in the formation of threonine hydroxamate. Staphylococcal extracts, as well as purified sortase, catalyze the hydroxylaminolysis of peptides bearing an LPXTG motif, a reaction that can be inhibited with sulfhydryl-modifying reagents. Replacement of the single conserved cysteine at position 184 of sortase with alanine abolishes enzyme activity. Thus, sortase appears to catalyze surface-protein anchoring by means of a transpeptidation reaction that captures cleaved polypeptides as thioester enzyme intermediates.

Crystal structures of the copper and nickel complexes of RNase A: Metal-induced interprotein interactions and identification of a novel copper binding motif

We report the crystal structures of the copper and nickel complexes of RNase A. The overall topology of these two complexes is similar to that of other RNase A structures. However, there are significant differences in the mode of binding of copper and nickel. There are two copper ions per molecule of the protein, but there is only one nickel ion per molecule of the protein. Significant changes occur in the interprotein interactions as a result of differences in the coordinating groups at the common binding site around His-105. Consequently, the copper- and nickel-ion-bound dimers of RNase A act as nucleation sites for generating different crystal lattices for the two complexes. A second copper ion is present at an active site residue His-119 for which all the ligands are from one molecule of the protein. At this second site, His-119 adopts an inactive conformation (B) induced by the copper. We have identified a novel copper binding motif involving the α-amino group and the N-terminal residues.

Immunostimulatory oligodeoxynucleotides containing the CpG motif are effective as immune adjuvants in tumor antigen immunization

Recent advances in our understanding of the immune response are allowing for the logical design of new approaches to cancer immunization. One area of interest is the development of new immune adjuvants. Immunostimulatory oligodeoxynucleotides containing the CpG motif (CpG ODN) can induce production of a wide variety of cytokines and activate B cells, monocytes, dendritic cells, and NK cells. Using the 38C13 B cell lymphoma model, we assessed whether CpG ODN can function as immune adjuvants in tumor antigen immunization. The idiotype served as the tumor antigen. Select CpG ODN were as effective as complete Freund’s adjuvant at inducing an antigen-specific antibody response but were associated with less toxicity. These CpG ODN induced a higher titer of antigen-specific IgG2a than did complete Freund’s adjuvant, suggesting an enhanced TH1 response. Mice immunized with CpG ODN as an adjuvant were protected from tumor challenge to a degree similar to that seen in mice immunized with complete Freund’s adjuvant. We conclude that CpG ODN are effective as immune adjuvants and are attractive as part of a tumor immunization strategy.

High-affinity binding of the Drosophila Numb phosphotyrosine-binding domain to peptides containing a Gly-Pro-(p)Tyr motif

The phosphotyrosine-binding (PTB) domain is a recently identified protein module that has been characterized as binding to phosphopeptides containing an NPXpY motif (X = any amino acid). We describe here a novel peptide sequence recognized by the PTB domain from Drosophila Numb (dNumb), a protein involved in cell fate determination and asymmetric cell division during the development of the Drosophila nervous system. Using a Tyr-oriented peptide library to screen for ligands, the dNumb PTB domain was found to bind selectively to peptides containing a YIGPYφ motif (φ represents a hydrophobic residue). A synthetic peptide containing this sequence bound specifically to the isolated dNumb PTB domain in solution with a dissociation constant (Kd) of 5.78 ± 0.74 μM. Interestingly, the affinity of this peptide for the dNumb PTB domain was increased (Kd = 1.41 ± 0.10 μM) when the second tyrosine in the sequence was phosphorylated. Amino acid substitution studies of the phosphopeptide demonstrated that a core motif of sequence GP(p)Y is required for high-affinity binding to the dNumb PTB domain. Nuclear magnetic resonance experiments performed on isotopically labeled protein complexed with either Tyr- or pTyr-containing peptides suggest that the same set of amino acids in the dNumb PTB domain is involved in binding both phosphorylated and nonphosphorylated forms of the peptide. The in vitro selectivity of the dNumb PTB domain is therefore markedly different from those of the Shc and IRS-1 PTB domains, in that it interacts preferentially with a GP(p)Y motif, rather than NPXpY, and does not absolutely require ligand phosphorylation for binding. Our results suggest that the PTB domain is a versatile protein module, capable of exhibiting varied binding specificities.