24 research outputs found

    Social Transfer of Pathogenic Fungus Promotes Active Immunisation in Ant Colonies

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    Social contact with fungus-exposed ants leads to pathogen transfer to healthy nest-mates, causing low-level infections. These micro-infections promote pathogen-specific immune gene expression and protective immunization of nest-mates

    Mechanism of inhibition of human glucose transporter GLUT1 is conserved between cytochalasin B and phenylalanine amides.

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    Cancerous cells have an acutely increased demand for energy, leading to increased levels of human glucose transporter 1 (hGLUT1). This up-regulation suggests hGLUT1 as a target for therapeutic inhibitors addressing a multitude of cancer types. Here, we present three inhibitor-bound, inward-open structures of WT-hGLUT1 crystallized with three different inhibitors: cytochalasin B, a nine-membered bicyclic ring fused to a 14-membered macrocycle, which has been described extensively in the literature of hGLUTs, and two previously undescribed Phe amide-derived inhibitors. Despite very different chemical backbones, all three compounds bind in the central cavity of the inward-open state of hGLUT1, and all binding sites overlap the glucose-binding site. The inhibitory action of the compounds was determined for hGLUT family members, hGLUT1–4, using cell-based assays, and compared with homology models for these hGLUT members. This comparison uncovered a probable basis for the observed differences in inhibition between family members. We pinpoint regions of the hGLUT proteins that can be targeted to achieve isoform selectivity, and show that these same regions are used for inhibitors with very distinct structural backbones. The inhibitor cocomplex structures of hGLUT1 provide an important structural insight for the design of more selective inhibitors for hGLUTs and hGLUT1 in particular

    Chromopynones are pseudo natural product glucose uptake inhibitors targeting glucose transporters GLUT-1 and -3

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    The principles guiding the design and synthesis of bioactive compounds based on natural product (NP) structure, such as biology-oriented synthesis (BIOS), are limited by their partial coverage of the NP-like chemical space of existing NPs and retainment of bioactivity in the corresponding compound collections. Here we propose and validate a concept to overcome these limitations by de novo combination of NP-derived fragments to structurally unprecedented ‘pseudo natural products’. Pseudo NPs inherit characteristic elements of NP structure yet enable the efficient exploration of areas of chemical space not covered by NP-derived chemotypes, and may possess novel bioactivities. We provide a proof of principle by designing, synthesizing and investigating the biological properties of chromopynone pseudo NPs that combine biosynthetically unrelated chromane- and tetrahydropyrimidinone NP fragments. We show that chromopynones define a glucose uptake inhibitor chemotype that selectively targets glucose transporters GLUT-1 and -3, inhibits cancer cell growth and promises to inspire new drug discovery programmes aimed at tumour metabolism

    The minimum amount of "matrix " needed for matrix-assisted pulsed laser deposition of biomolecules

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    The ability of matrix-assisted pulsed laser evaporation (MAPLE) technique to transfer and deposit high-quality thin organic, bioorganic, and composite films with minimum chemical modification of the target material has been utilized in numerous applications. One of the outstanding problems in MAPLE film deposition, however, is the presence of residual solvent (matrix) codeposited with the polymer material and adversely affecting the quality of the deposited films. In this work, we investigate the possibility of alleviating this problem by reducing the amount of matrix in the target. A series of coarse-grained molecular dynamics simulations are performed for a model lysozyme–water system, where the water serves the role of volatile “matrix” that drives the ejection of the biomolecules. The simulations reveal a remarkable ability of a small (5–10 wt %) amount of matrix to cause the ejection of intact bioorganic molecules. The results obtained for different laser fluences and water concentrations are used to establish a “processing map” of the regimes of molecular ejection in matrix-assisted pulsed laser deposition. The computational predictions are supported by the experimental observation of the ejection of intact lysozyme molecules from pressed lysozyme targets containing small amounts of residual water. The results of this study suggest a new approach for deposition of thin films of bioorganic molecules with minimum chemical modification of the molecular structure and minimum involvement of solvent into the deposition process
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