Abstract:

We describe the nickel(II)‐mediated self‐assembly of a multimeric DNA binder composed by two metal‐chelating peptides derived from a bZIP transcription factor ( brHis 2 ) and one short AT‐hook domain equipped with two bipyridine ligands ( HkBpy 2 ). These peptides reversibly assemble in the presence of Ni(II) ions at selected DNA sequences of 13 base pairs.

External link: https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202001277

Abstract: The generation of catalytically active metalloproteins inside living mammalian cells is a major research challenge at the interface between catalysis and cell biology. Herein we demonstrate that basic domains of bZIP transcription factors, mutated to include two histidine residues at i, i+4 positions, react with palladium (II) sources to generate catalytically active, stapled pallado‐miniproteins. The resulting constrained peptides are efficiently internalized into living mammalian cells, where they can perform palladium‐promoted depropargylation reactions, without cellular fixation. Control experiments confirm the requirement of the peptide scaffolding and the palladium staple for attaining the intracellular reactivity.

External link: https://onlinelibrary.wiley.com/doi/10.1002/anie.202002032

Abstract:

When nanoparticles (NPs) are exposed to biological media, proteins are adsorbed, forming a so-called protein corona (PC). This cloud of protein aggregates hampers the targeting and transport capabilities of the NPs, thereby compromising their biomedical applications. Therefore, there is a high interest in the development of technologies that allow control over PC formation, as this would provide a handle to manipulate NPs in biological fluids. We present a strategy that enables the reversible disruption of the PC using external stimuli, thereby allowing a precise regulation of NP cellular uptake. The approach, demonstrated for gold nanoparticles (AuNPs), is based on a biorthogonal, supramolecular host–guest interactions between an anionic dye bound to the AuNP surface and a positively charged macromolecular cage. This supramolecular complex effectively behaves as a zwitterionic NP ligand, which is able not only to prevent PC formation but also to disrupt a previously formed hard corona. With this supramolecular stimulus, the cellular internalization of AuNPs can be enhanced by up to 30-fold in some cases, and even NP cellular uptake in phagocytic cells can be regulated. Additionally, we demonstrate that the conditional cell uptake of purposely designed gold nanorods can be used to selectively enhance photothermal cell death.

External link: https://twitter.com/MetBioCat/status/1235837116090691585

External link: https://www.usc.es/ciqus/en/noticias/el-investigador-del-ciqus-christian-vidal-premio-talento-mozo-de-la-xunta-de-galicia

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