Technology and teaching in higher education: A simulation applied to the integration of concepts taught in postgraduate courses

Introducción: El objetivo de este trabajo fue implementar tecnologías de la información y la comunicación (TIC) a nivel de posgrado. En este caso particular se usó USINA, un simulador para la toma de decisiones diseñado por el Centro de Innovaciones en Tecnología y Pedagogía (CITEP), de la Universidad de Buenos Aires. Ésta permite trabajar con narraciones, estudio de casos y utilizar el “error” como método pedagógico. Métodos: 1) Diseñar una secuencia de pantallas para ser montadas en USINA utilizándola como herramienta de integración de conceptos en dos cursos de posgrado: Downstream Processing de proteínas (DSP) y Aplicaciones, Síntesis y Análisis de Péptidos Sintéticos (ASAP). 2) Aplicar una encuesta anónima para evaluar la eficiencia de USINA. 3) Realizar una clase presencial para intercambiar opiniones sobre la experiencia. Resultados y Discusión: En ambos cursos (DSP y ASAP) la experiencia resultó exitosa. El alumnado consideró que el uso de USINA permitió el andamiaje de conocimientos y la integración de conceptos al situarlo en el rol de experto. El uso de las TIC en los niveles educativos superiores sigue siendo una asignatura pendiente. A través de la experiencia aquí analizada, se abre la posibilidad de llevar esta herramienta a cursos de pregrado y con mayor número de estudiantesIntroduction: The aim of this work was to implement information and communication technologies (ICTs) at postgraduate level. In this particular case, USINA, a decision-making simulator designed by the Center for Innovation in Technology and Education (CITEP), of the University of Buenos Aires, was used. It allows working with stories, case studies and uses the "error" as a teaching method. Methods: 1) Design a sequence of screens to be mounted in the USINA platform to use it as a tool for the integration of concepts in two postgraduate courses: Protein Downstream Processing (DSP) and Applications, Synthesis and Analysis of Synthetic Peptides (ASAP). 2) Apply anonymous quiz to evaluate the efficiency of USINA. 3) Perform a class attendance to exchange opinions on the experience. Results: During both courses (DSP and ASAP) the experience was very successful. The students felt that the use of USINA enhanced learning and helped integrating concepts by situating them in the role of experts. Discussion: The use of ICTs in higher levels of education remains a pending issue. Through the experience here analyzed the possibility to bring this tool to undergraduate courses and more students is opene

Las tecnologías y la enseñanza en la educación superior. Un simulador aplicado a la integración de conceptos enseñados en cursos de posgrado

Introduction: The aim of this work was to implement information and communication technologies (ICTs) at postgraduate level. In this particular case, USINA, a decision-making simulator designed by the Center for Innovation in Technology and Education (CITEP), of the University of Buenos Aires, was used. It allows working with stories, case studies and uses the "error" as a teaching method. Methods: 1) Design a sequence of screens to be mounted in the USINA platform to use it as a tool for the integration of concepts in two postgraduate courses: Protein Downstream Processing (DSP) and Applications, Synthesis and Analysis of Synthetic Peptides (ASAP). 2) Apply anonymous quiz to evaluate the efficiency of USINA. 3) Perform a class attendance to exchange opinions on the experience. Results: During both courses (DSP and ASAP) the experience was very successful. The students felt that the use of USINA enhanced learning and helped integrating concepts by situating them in the role of experts. Discussion: The use of ICTs in higher levels of education remains a pending issue. Through the experience here analyzed the possibility to bring this tool to undergraduate courses and more students is opened.Introducción: El objetivo de este trabajo fue implementar tecnologías de la información y la comunicación (TIC) a nivel de posgrado. En este caso particular se usó USINA, un simulador para la toma de decisiones diseñado por el Centro de Innovaciones en Tecnología y Pedagogía (CITEP), de la Universidad de Buenos Aires. Ésta permite trabajar con narraciones, estudio de casos y utilizar el “error” como método pedagógico. Métodos: 1) Diseñar una secuencia de pantallas para ser montadas en USINA utilizándola como herramienta de integración de conceptos en dos cursos de posgrado: Downstream Processing de proteínas (DSP) y Aplicaciones, Síntesis y Análisis de Péptidos Sintéticos (ASAP). 2) Aplicar una encuesta anónima para evaluar la eficiencia de USINA. 3) Realizar una clase presencial para intercambiar opiniones sobre la experiencia. Resultados y Discusión: En ambos cursos (DSP y ASAP) la experiencia resultó exitosa. El alumnado consideró que el uso de USINA permitió el andamiaje de conocimientos y la integración de conceptos al situarlo en el rol de experto. El uso de las TIC en los niveles educativos superiores sigue siendo una asignatura pendiente. A través de la experiencia aquí analizada, se abre la posibilidad de llevar esta herramienta a cursos de pregrado y con mayor número de estudiantes

Design and Synthesis of Peptides from Phoneutria nigriventer δ-Ctenitoxin-Pn2a for Antivenom Production

The venom toxin δ-ctenitoxin-Pn2a of the spider Phoneutria nigriventer can cause severe envenomation in humans. Furthermore, the cystine-knot motif of δ-ctenitoxin-Pn2a provides exceptional stability, thereby hampering immune response activation. Here we identified epitope G34YFWIAWYKLANCKK48 from δ-ctenitoxin-Pn2a through the Immune Epitope Database Analysis Resource and used it to design antigenic peptides. The Cys residue was replaced by α-aminobutyric acid (Abu) to prevent disulfide bond formation. To increase the immunogenicity of these molecules, branched and N-palmitoylated versions were synthesized. Ac-GYFWIAWYKLAN-Abu-KKG-NH2 (A), Palm-GYFWIAWYKLAN-Abu-KKG-NH2 (B) and (Ac-GYFWIAWYKLAN-Abu-KK)2-KG-NH2 (C) were prepared by solid-phase synthesis and their identity was confirmed by ESI–MS. They were then studied by RP-HPLC and all the chromatograms obtained showed only one main peak. Cytotoxicity was evaluated on the murine macrophage cell line RAW 264.7 using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay in the presence of increasing doses of each peptide (0.25–10.0 µM). Peptide A did not show cytotoxicity between 0.25 and 10.0 µM, while B and C did at concentrations equal or over 0.5 and 10.0 respectively. The cellular distribution of NF-κB was examined by immunofluorescence after exposing macrophages to 0.5 µM of each peptide. Early activation was observed for all three peptides, thereby indicating that they are promising immunogens for antivenom production. Nevertheless, in vivo tests are still required to assess their immunogenic capacity and whether the antibodies generated can confer protection against the venom.The authors thank Prof. Dr. Elba Vazquez from Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Laboratorio de Inflamación y Cáncer, (IQUIBICEN), for kindly donating the Raw 264.7 cells used in the experiments. This work was partially supported by the Agencia Nacional de Promoción de la Investigación, el Desarrollo Tecnológico y la Innovación de la República Argentina (PICT-2018-00498, PICT-2020-Serie-A-02579, PICT-2021-58) and the Universidad de Buenos Aires, Argentina (20020170100030BA, 20020170100128BA). SAC is a researcher of the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET).Peer reviewe

An inhibitory mechanism of action of coiled‐coil peptides against type three secretion system from enteropathogenic Escherichia coli

Human pathogenic gram‐negative bacteria, such as enteropathogenic Escherichia coli (EPEC), rely on type III secretion systems (T3SS) to translocate virulence factors directly into host cells. The coiled‐coil domains present in the structural proteins of T3SS are conformed by amphipathic alpha‐helical structures that play an important role in the protein‐protein interaction and are essential for the assembly of the translocation complex. To investigate the inhibitory capacity of these domains on the T3SS of EPEC, we synthesized peptides between 7 and 34 amino acids based on the coiled‐coil domains of proteins that make up this secretion system. This analysis was performed through in vitro hemolysis assays by assessing the reduction of T3SS‐dependent red blood cell lysis in the presence of the synthesized peptides. After confirming its inhibitory capacity, we performed molecular modeling assays using combined techniques, docking‐molecular dynamic simulations, and quantum‐mechanic calculations of the various peptide‐protein complexes, to improve the affinity of the peptides to the target proteins selected from T3SS. These techniques allowed us to demonstrate that the peptides with greater inhibitory activity, directed against the coiled‐coil domain of the C‐terminal region of EspA, present favorable hydrophobic and hydrogen bond molecular interactions. Particularly, the hydrogen bond component is responsible for the stabilization of the peptide‐protein complex. This study demonstrates that compounds targeting T3SS from pathogenic bacteria can indeed inhibit bacterial infection by presenting a higher specificity than broad‐spectrum antibiotics. In turn, these peptides could be taken as initial structures to design and synthesize new compounds that mimic their inhibitory pharmacophoric pattern.Instituto de BiotecnologíaFil: Larzabal, Mariano.Instituto Nacional de Tecnología Agropecuaria (INTA). UEDD IABIMO. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Baldoni, Hector A. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Matemática Aplicada San Luis; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Suvire, Fernando D. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto Multidisciplinario de Investigaciones Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Curto, Lucrecia M. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gomez, Gabriela E. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marques Da Silva, Wanderson. Instituto Nacional de Tecnología Agropecuaria (INTA). UEDD IABIMO. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Giudicessi, Silvana L. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Cátedra de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Camperi, Silvia A. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Cátedra de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Delfino, Jose M. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). UEDD IABIMO. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Enriz, Daniel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto Multidisciplinario de Investigaciones Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Friendly Strategy to Prepare Encoded One Bead–One Compound Cyclic Peptide Library

One bead–one peptide libraries allow the screening of suitable ligands for any target protein. Short cyclic peptides are ideal ligands for affinity chromatography because of their high affinity and selectivity for the target protein and stability against proteases. We designed a library synthesis strategy to facilitate the identification of cyclic peptides by MS consisting of (a) sequential incorporation of a mixture of Fmoc-Ala-OH and Fmoc-Asp­[2-phenylisopropyl (OPp)]-OH (15:85) to Gly-oxymethylbenzamide-ChemMatrix (Gly-HMBA-CM) resin, (b) synthesis of the combinatorial library on the resin by the divide–couple–recombine method, (c) removal of OPp with 4% TFA, (d) peptide cyclization on solid phase through side-chain Asp and amino terminus, and (e) removal of side chain protecting groups with a 95% TFA cocktail. Peptides were cleaved from the beads with ammonia and the linear code was sequenced by MALDI-TOF MS/MS. The high capacity of ChemMatrix resin together with the sensitivity of MS allows code sequencing from a single bead

Thaulin-1: The first antimicrobial peptide isolated from the skin of a Patagonian frog Pleurodema thaul (Anura: Leptodactylidae: Leiuperinae) with activity against Escherichia coli

Patagonia's biodiversity has been explored from many points of view, however, skin secretions of native amphibians have not been evaluated for antimicrobial peptide research until now. In this sense, Pleurodema thaul is the first amphibian specie to be studied from this large region of South America. Analysis of cDNA-encoding peptide in skin samples allowed identification of four new antimicrobial peptides. The predicted mature peptides were synthesized and all of them showed weak or null antimicrobial activity against Klebsiella pneumoniae, Staphylococcus aureus and Escherichia coli with the exception of thaulin-1, a cationic 26-residue linear, amphipathic, Gly- and Leu-rich peptide with moderate antimicrobial activity against E. coli (MIC of 24.7 M). AFM and SPR studies suggested a preferential interaction between these peptides and bacterial membranes. Cytotoxicity assays showed that thaulin peptides had minimal effects at MIC concentrations towards human and animal cells. These are the first peptides described for amphibians of the Pleurodema genus. These findings highlight the potential of the Patagonian region's unexplored biodiversity as a source for new molecule discovery.This work was partially supported by grants from the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (PIP N° 11220120100050CO), and the Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT) (PICT N° 1199). M.M.M., L.O.P., S.A.C. and N.G.B. are researchers at CONICET. Work in AMT laboratory was supported by Project “NORTE-07-0124-FEDER-000002-Host-Pathogen Interactions” cofunded by Programa Operacional Regional do Norte under QREN, through FEDER (NORTE-07-0124-FEDER-000002-Host-Pathogen Interactions) and FCT. (SFRH/BD/97995/2013, SFRH/BD/93766/2013 and UID/MULTI/04378/2013) A.P. and A.G.G.A. are gratefully to FCT by their grants SFRH/BD/97995/2013 and SFRH/BD/93766/2013 respectively, financed by POPH–QREN–Tipologia 4.1–Formação Avançada, subsidized by Fundo Social Europeu and Ministério da Ciência, Tecnologia e Ensino Superior. The authors thank N.L. Olivera for logistic support and helpful discussions regarding the article. P.E. thanks CNPq for PVE grant no. 400398/2014-1, and is supported by FCTvia the project UID/MULTI/04378/2013