Unravelling the complexity of the extracellular vesicle landscape with advanced proteomics

Ikerbasque, Basque Foundation for Science European Proteomics Infrastructure Consortium providing access.N

Divinyl Sulfone Cross-Linked Cyclodextrin-Based Polymeric Materials: Synthesis and Applications as Sorbents and Encapsulating Agents

The aim of this study was to evaluate the crosslinking abilities of divinyl sulfone (DVS) for the preparation of novel water-insoluble cyclodextrin-based polymers (CDPs) capable of forming inclusion complexes with different guest molecules. Reaction of DVS with native α-cyclodextrin (α-CD), β-cyclodextrin (β-CD) and/or starch generates a variety of homo- and hetero-CDPs with different degrees of crosslinking as a function of the reactants’ stoichiometric ratio. The novel materials were characterized by powder X-ray diffraction, electron microscopy and for their sorption of phenol and 4-nitrophenol. They were further evaluated as sorbents with phenolic pollutants (bisphenol A and β-naphthol) and bioactive compounds (the hormone progesterone and curcumin). Data obtained from the inclusion experiments show that the degree of cross-linking has a minor influence on the yield of inclusion complex formation and highlight the important role of the CDs, supporting a sorption process based on the formation of inclusion complexes. In general, the inclusion processes are better described by a Freundlich isotherm although an important number of them can also be fitted to the Langmuir isotherm with R2 ≥ 0.9, suggesting a sorption onto a monolayer of homogeneous sites

Mouse Stbd1 is N-myristoylated and affects ER–mitochondria association and mitochondrial morphology

Starch binding domain-containing protein 1 (Stbd1) is a carbohydrate-binding protein that has been proposed to be a selective autophagy receptor for glycogen. Here, we show that mouse Stbd1 is a transmembrane endoplasmic reticulum (ER)-resident protein with the capacity to induce the formation of organized ER structures in HeLa cells. In addition to bulk ER, Stbd1 was found to localize to mitochondria-associated membranes (MAMs), which represent regions of close apposition between the ER and mitochondria. We demonstrate that N-myristoylation and binding of Stbd1 to glycogen act as major determinants of its subcellular targeting. Moreover, overexpression of non-myristoylated Stbd1 enhanced the association between ER and mitochondria, and further induced prominent mitochondrial fragmentation and clustering. Conversely, shRNA-mediated Stbd1 silencing resulted in an increase in the spacing between ER and mitochondria, and an altered morphology of the mitochondrial network, suggesting elevated fusion and interconnectivity of mitochondria. Our data unravel the molecular mechanism underlying Stbd1 subcellular targeting, support and expand its proposed function as a selective autophagy receptor for glycogen and uncover a new role for the protein in the physical association between ER and mitochondria

Beauveria bassiana rewires molecular mechanisms related to growth and defense in tomato

Plant roots can exploit beneficial associations with soil-inhabiting microbes, promoting growth and expanding the immune capacity of the host plant. In this work, we aimed to provide new information on changes occurring in tomato interacting with the beneficial fungus Beauveria bassiana. The tomato leaf proteome revealed perturbed molecular pathways during the establishment of the plant–fungus relationship. In the early stages of colonization (5–7 d), proteins related to defense responses to the fungus were down-regulated and proteins related to calcium transport were up-regulated. At later time points (12–19 d after colonization), up-regulation of molecular pathways linked to protein/amino acid turnover and to biosynthesis of energy compounds suggests beneficial interaction enhancing plant growth and development. At the later stage, the profile of leaf hormones and related compounds was also investigated, highlighting up-regulation of those related to plant growth and defense. Finally, B. bassiana colonization was found to improve plant resistance to Botrytis cinerea, impacting plant oxidative damage. Overall, our findings further expand current knowledge on the possible mechanisms underlying the beneficial role of B. bassiana in tomato plants

Fragment-derived inhibitors of human N-myristoyltransferase block capsid assembly and replication of the common cold virus

Rhinoviruses (RVs) are the pathogens most often responsible for the common cold, and are a frequent cause of exacerbations in asthma, chronic obstructive pulmonary disease and cystic fibrosis. Here we report the discovery of IMP-1088, a picomolar dual inhibitor of the human N-myristoyltransferases NMT1 and NMT2, and use it to demonstrate that pharmacological inhibition of host-cell N-myristoylation rapidly and completely prevents rhinoviral replication without inducing cytotoxicity. The identification of cooperative binding between weak-binding fragments led to rapid inhibitor optimization through fragment reconstruction, structure-guided fragment linking and conformational control over linker geometry. We show that inhibition of the co-translational myristoylation of a specific virus-encoded protein (VP0) by IMP-1088 potently blocks a key step in viral capsid assembly, to deliver a low nanomolar antiviral activity against multiple RV strains, poliovirus and foot and-mouth disease virus, and protection of cells against virus-induced killing, highlighting the potential of host myristoylation as a drug target in picornaviral infections

Vinilsulfonas, azidas y alquinos. Aplicaciones tecnológicas y biotecnológicas

Esta Tesis Doctoral ha sido realizada gracias a una beca predoctoral concedida por el Ministerio de Educación y Ciencia (FPU‐AP‐2003‐4773) y a la financiación con cargo a fondos del grupo FQM‐208 “Química de Carbohidratos: Síntesis, Reactividad y Diseño Teórico”.Dentro del concepto de click chemistry las cicloadiciones 1,3-dipolares de azidas y alquinos terminales catalizadas por Cu(I) (CuAAC) son las que han alcanzado un mayor grado de desarrollo y aplicación y se consideran el ejemplo fundamental dentro de este concepto. Desde el descubrimiento de la catálisis de Cu(I) en el año 2002 por los grupos de Meldal y Sharpless el interés por esta reacción ha crecido exponencialmente y no sólo en síntesis orgánica, sino en otros campos como ciencias de los materiales y ciencias biomédicas. Por otro lado, las vinilsulfonas son bien conocidas por su utilidad como intermedios en síntesis orgánica. Estos compuestos han demostrado ser reactivos de síntesis muy versátiles como aceptores de Michael en adiciones conjugadas de tipo 1,4 y en reacciones de cicloadición. Además, este grupo funcional también ha mostrado su capacidad para inhibir potencialmente una variedad de procesos enzimáticos proporcionando unas propiedades únicas que se pueden explotar en el diseño de fármacos. El objetivo general de la presente Tesis Doctoral es explotar la capacidad de las reacciones de CuAAC para interconectar de forma fácil y eficiente diversas estructuras y poner de manifiesto la enorme potencialidad que esconden las vinilsulfonas como grupo reactivo en diversas aplicaciones. Específicamente se han explorado aplicaciones en el campo de las ciencias ómicas y en el campo de la eliminación de contaminantes.Tesis Univ. Granada.Ministerio de Educación y Ciencia (FPU‐AP‐2003‐4773)FQM‐20

Divinyl Sulfone Cross-Linked Cyclodextrin-Based Polymeric Materials: Synthesis and Applications as Sorbents and Encapsulating Agents

The aim of this study was to evaluate the crosslinking abilities of divinyl sulfone (DVS) for the preparation of novel water-insoluble cyclodextrin-based polymers (CDPs) capable of forming inclusion complexes with different guest molecules. Reaction of DVS with native α-cyclodextrin (α-CD), β-cyclodextrin (β-CD) and/or starch generates a variety of homo- and hetero-CDPs with different degrees of crosslinking as a function of the reactants’ stoichiometric ratio. The novel materials were characterized by powder X-ray diffraction, electron microscopy and for their sorption of phenol and 4-nitrophenol. They were further evaluated as sorbents with phenolic pollutants (bisphenol A and β-naphthol) and bioactive compounds (the hormone progesterone and curcumin). Data obtained from the inclusion experiments show that the degree of cross-linking has a minor influence on the yield of inclusion complex formation and highlight the important role of the CDs, supporting a sorption process based on the formation of inclusion complexes. In general, the inclusion processes are better described by a Freundlich isotherm although an important number of them can also be fitted to the Langmuir isotherm with R2 ≥ 0.9, suggesting a sorption onto a monolayer of homogeneous sites

Polymer matrices based on plysaccharides and cyclodextrins

Número de publicación: ES2334756 B1. Número de solicitud: 200901744.La presente invención se refiere a nuevos materiales basados ​​en matrices de polímeros obtenidos a partir de polisacáridos, a los métodos para la obtención del mismo y a los usos de los mismos. Más particularmente, la invención se refiere al uso de dichos materiales basados ​​en almidón, dextrina o ciclodextrinas para el secuestro de contaminantes orgánicos e inorgánicos y para la purificación de agua.The present invention relates to novel materials based on polymer matrices obtained from polysaccharides, to the methods for obtaining same and to the uses thereof. More particularly, the invention relates to the use of said materials based on starch, dextrin or cyclodextrins to sequester organic and inorganic contaminants and for the purification of water.Universidad de Granad

Bicyclization and tethering to albumin yields long-acting Peptide antagonists

Proteolytically stable peptide architectures are required for the development of long-acting peptide therapeutics. In this work, we found that a phage-selected bicyclic peptide antagonist exhibits an unusually high stability in vivo and subsequently deciphered the underlying mechanisms of peptide stabilization. We found that the bicyclic peptide was significantly more stable than its constituent rings synthesized as two individual macrocycles. The two rings protect each other from proteolysis when linked together, conceivably by constraining the conformation and/or by mutually shielding regions prone to proteolysis. A second stabilization mechanism was found when the bicyclic peptide was linked to an albumin-binding peptide to prevent its rapid renal clearance. The bicyclic peptide conjugate not only circulated 50-fold longer (t(1/2) = 24 h) but also became entirely resistant to proteolysis when tethered to the long-lived serum protein. The bicyclic peptide format overcomes a limitation faced by many peptide leads and appears to be suitable for the generation of long-acting peptide therapeutics

Bicyclic Peptides Conjugated to an Albumin-Binding Tag Diffuse Efficiently into Solid Tumors

Monoclonal antibodies have long in vivo half-lives and reach high concentrations in tumors but cannot access all regions in the tissue, whereas smaller ligands such as peptides distribute better but are limited by low concentrations due to fast renal clearance. A potential solution to this problem might be offered by peptide-based ligands that are conjugated to an albumin-binding tag, and thus have a long plasma half-life. Herein, we tested if a small ligand based on a bicyclic peptide (1.9 kDa) conjugated to an albumin- binding peptide (2.3 kDa) can diffuse into tissues. Although the peptide conjugate (4.6 kDa) was most of the time bound to the large protein serum albumin (66.5 kDa), it diffused deeply into tissues and reached high nanomolar concentrations in wide areas of solid tumors. Most of the peptide conjugate isolated from tumor tissue was found to be fully intact 24 hours after administration. Because of its noncovalent interaction with albumin, the bicyclic peptide might dissociate to diffuse to tumor regions that are not accessible to larger ligands. Bicyclic peptides having high binding affinity for targets of interest and being proteolytically stable can be evolved by phage display; in conjunction with albumin-binding tags, they offer a promising format to access targets in solid tumors. (C) 2014 AACR