72 research outputs found
Mechanical Isolation of Highly Stable Antimonene under Ambient Conditions
Using mechanical exfoliation combined with a controlled double step transfer
procedure we demonstrate that single layers of antimony can be readily
produced. These flakes are not significantly contaminated upon exposure to
ambient conditions and they do not react with water. DFT calculations confirm
our experimental observations and predict a band gap of 1.2-1.3 eV (ambient
conditions) for single layer antimonene, which is smaller than that calculated
under vacuum conditions at 0 K. Our work confirms antimonene as a highly stable
2D material with promising relevant applications in optoelectronics.Comment: main paper: 5 pages, 4 figures supporting: 9 pages, 7 figures,
Advanced Materials, 201
Catalytically Active Imine-based Covalent Organic Frameworks for Detoxification of Nerve Agent Simulants in Aqueous Media
A series of imine-based covalent organic frameworks decorated in their cavities with
di erent alkynyl, pyrrolidine, and N-methylpyrrolidine functional groups have been synthetized.
These materials exhibit catalytic activity in aqueous media for the hydrolytic detoxification of nerve
agents, as exemplified with nerve gas simulant diisopropylfluorophosphate (DIFP). These preliminary
results suggest imine-based covalent organic frameworks (COFs) as promising materials for
detoxification of highly toxic molecules.MINECO (MAT2016-77608-C3-1-P and 2-P, CTQ2017-84692-R)
and EU FEDER fundin
1,3,5-Triazines with aromatic amino acids: Exploring their potential as lectin mimetics
VII Escuela de verano de la SEQT, Sociedad Española de QuĂmica TerapeĂștica, Barcelona, 19-21 Julio, 202
Peptidoglycan editing in non-proliferating intracellular Salmonella as source of interference with immune signaling
This work was funded by grants
PID2020-112971GB-I00/10.13039/501100011033
(F.G-dP.) and PID2019-104070RB-C21 (S.V.) of
the Spanish Ministry of Science and Innovation,
VR2018-02823 of the Swedish Research Council
(F.C.), KAW2012.0184 of the Knut and Alice
Wallenberg Foundation (F.C.), and SMK2062 of the
Kempe Foundation (F.C.
Multivalent Tryptophan- and Tyrosine-Containing [60]Fullerene Hexa-Adducts as Dual HIV and Enterovirus A71 Entry Inhibitors
Unprecedented 3D hexa-adducts of [60]fullerene peripherally decorated with twelve tryptophan (Trp) or tyrosine (Tyr) residues have been synthesized. Studies on the antiviral activity of these novel compounds against HIV and EV71 reveal that they are much more potent against HIV and equally active against EV71 than the previously described dendrimer prototypes AL-385 and AL-463, which possess the same number of Trp/Tyr residues on the periphery but attached to a smaller and more flexible pentaerythritol core. These results demonstrate the relevance of the globular 3D presentation of the peripheral groups (Trp/Tyr) as well as the length of the spacer connecting them to the central core to interact with the viral envelopes, particularly in the case of HIV, and support the hypothesis that [60]fullerene can be an alternative and attractive biocompatible carbon-based scaffold for this type of highly symmetrical dendrimers. In addition, the functionalized fullerenes here described, which display twelve peripheral negatively charged indole moieties on their globular surface, define a new and versatile class of compounds with a promising potential in biomedical applications.status: publishe
Morpho-sedimentary dynamics of a micro-tidal mixed sand and gravel beach, Playa Granada, southern Spain
publisher: Elsevier articletitle: Morpho-sedimentary dynamics of a micro-tidal mixed sand and gravel beach, Playa Granada, southern Spain journaltitle: Marine Geology articlelink: http://dx.doi.org/10.1016/j.margeo.2016.05.003 content_type: article copyright: © 2016 Elsevier B.V. All rights reserved
Peptidoglycan editing in non-proliferating intracellular Salmonella as source of interference with immune signaling
Salmonella enterica causes intracellular infections that can be limited to the intestine or
spread to deeper tissues. In most cases, intracellular bacteria show moderate growth. How
these bacteria face host defenses that recognize peptidoglycan, is poorly understood. Here,
we report a high-resolution structural analysis of the minute amounts of peptidoglycan puri-
fied from S. enterica serovar Typhimurium (S. Typhimurium) infecting fibroblasts, a cell type
in which this pathogen undergoes moderate growth and persists for days intracellularly. The
peptidoglycan of these non-proliferating bacteria contains atypical crosslinked muropep-
tides with stem peptides trimmed at the L-alanine-D-glutamic acid-(Îł) or D-glutamic acid-(Îł)-
meso-diaminopimelic acid motifs, both sensed by intracellular immune receptors. This pepti-
doglycan has a reduced glycan chain average length and ~30% increase in the L,D-cross-
link, a type of bridge shared by all the atypical crosslinked muropeptides identified. The L,D-
transpeptidases LdtD (YcbB) and LdtE (YnhG) are responsible for the formation of these L,
D-bridges in the peptidoglycan of intracellular bacteria. We also identified in a fraction of
muropeptides an unprecedented modification in the peptidoglycan of intracellular S. Typhi-
murium consisting of the amino alcohol alaninol replacing the terminal (fourth) D-alanine.
Alaninol was still detectable in the peptidoglycan of a double mutant lacking LdtD and LdtE,
thereby ruling out the contribution of these enzymes to this chemical modification. Remark-
ably, all multiple mutants tested lacking candidate enzymes that either trim stem peptides or
form the L,D-bridges retain the capacity to modify the terminal D-alanine to alaninol and all
attenuate NF-ÎșB nuclear translocation. These data inferred a potential role of alaninol-con-
taining muropeptides in attenuating pro-inflammatory signaling, which was confirmed with a
synthetic tetrapeptide bearing such amino alcohol. We suggest that the modification of D-
alanine to alaninol in the peptidoglycan of non-proliferating intracellular S. Typhimurium is
an editing process exploited by this pathogen to evade immune recognition inside host cells.This work was funded by grants
PID2020-112971GB-I00/10.13039/501100011033
(F.G-dP.) and PID2019-104070RB-C21 (S.V.) of
the Spanish Ministry of Science and Innovation,
VR2018-02823 of the Swedish Research Council
(F.C.), KAW2012.0184 of the Knut and Alice
Wallenberg Foundation (F.C.), and SMK2062 of the
Kempe Foundation (F.C.). S.C. was recipient of an
EMBO Short-Term Fellowship number 6426 for a
stay in the lab of F.C. The funders had no role in
study design, data collection and analysis, decision
to publish, or preparation of the manuscriptPeer reviewe
Pharmacological Elevation of Cellular Dihydrosphingomyelin Provides a Novel Antiviral Strategy against West Nile Virus Infection
The flavivirus life cycle is strictly dependent on cellular lipid metabolism. Polyphenols like gallic acid and its derivatives are promising lead compounds for new therapeutic agents as they can exert multiple pharmacological activities, including the alteration of lipid metabolism. The evaluation of our collection of polyphenols against West Nile virus (WNV), a representative medically relevant flavivirus, led to the identification of N,N'-(dodecane-1,12-diyl)bis(3,4,5-trihydroxybenzamide) and its 2,3,4-trihydroxybenzamide regioisomer as selective antivirals with low cytotoxicity and high antiviral activity (half-maximal effective concentrations [EC50s] of 2.2 and 0.24âÎŒM, respectively, in Vero cells; EC50s of 2.2 and 1.9âÎŒM, respectively, in SH-SY5Y cells). These polyphenols also inhibited the multiplication of other flaviviruses, namely, Usutu, dengue, and Zika viruses, exhibiting lower antiviral or negligible antiviral activity against other RNA viruses. The mechanism underlying their antiviral activity against WNV involved the alteration of sphingolipid metabolism. These compounds inhibited ceramide desaturase (Des1), promoting the accumulation of dihydrosphingomyelin (dhSM), a minor component of cellular sphingolipids with important roles in membrane properties. The addition of exogenous dhSM or Des1 blockage by using the reference inhibitor GT-11 {N-[(1R,2S)-2-hydroxy-1-hydroxymethyl-2-(2-tridecyl-1-cyclopropenyl)ethyl]octanamide} confirmed the involvement of this pathway in WNV infection. These results unveil the potential of novel antiviral strategies based on the modulation of the cellular levels of dhSM and Des1 activity for the control of flavivirus infection.We thank Theodore C. Pierson (National Institutes of Health, USA) for the subgenomic replicon of WNV.
This work was supported by the Spanish Ministry of Science and Innovation AEI/10.13039/501100011033 under grants PID2019-105117RR-C21 (to M.A.M.-A.), PID2019-105117RR-C22 (to M.-J.P.-P.), and PID2020-119195RJ-I00 (to N.J.d.O.) and by the AECSIC under grant PIE-201980E100 (to M.-J.P.-P. and A.S.-F.). This research work was also funded by the European Commission-NextGenerationEU (regulation EU 2020/2094) through CSICâs Global Health Platform (PTI Salud Global). P.M.-C. was supported by an FPI fellowship (PRE2020-093374) from AEI/10.13039/501100011033. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.Peer reviewe
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