33 research outputs found

    Bioorthogonal Conjugation of Transition Organometallic Complexes to Peptides and Proteins: Strategies and Applications

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    International audienceThe advent of bioorthogonal chemistry has revolutionized the common practices in protein bioconjugation and contributed to a large extent to the development of chemical biology, a discipline aimed at studying biological/biochemical processes/events in their natural setting (living cells, whole organisms) using dedicated chemical tools. This minireview intends to provide an up‐to‐date overview on the various bioorthogonal strategies implemented for the conjugation of transition organometallic entities to peptides, peptide nucleic acids and proteins with a focus on targeted applications, i.e. fluorescence‐ or radio‐labeling for imaging, controlled delivery of therapeutic agents and bioanalysis

    ‘Clickable’ cyclopentadienyl iron carbonyl complexes for bioorthogonal conjugation of mid-infrared labels to a model protein and PAMAM dendrimer

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    International audienceOwing to the intrinsic limitations of the conventional bioconjugation methods involving native nucleophilic functions of proteins, we sought to develop alternative approaches to introduce metallocarbonyl infrared labels onto proteins on the basis of the [3 + 2] dipolar azide‐alkyne cycloaddition (AAC). To this end, two cyclopentadienyl iron dicarbonyl (Fp) complexes carrying a terminal or a strained alkyne handle were synthesized. Their reactivity was examined towards a model protein and poly (amidoamine) (PAMAM) dendrimer, both carrying azido groups. While the copper (I)‐catalysed azide‐alkyne cycloaddition (CuAAC) proceeded smoothly with the terminal alkyne metallocarbonyl derivative, labelling by strain‐promoted azide‐alkyne cycloaddition (SPAAC) was less successful in terms of final coupling ratios. Infrared spectral characterization of the bioconjugates showed the presence of two bands in the 2000 cm−1 region, owing to the stretching vibration modes of the carbonyl ligands of the Fp entities

    Synthesis, Electrochemical and Fluorescence Properties of the First Fluorescent Member of the Ferrocifen Family and of Its Oxidized Derivatives

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    The first fluorescent ferrociphenol derivative (P797) has been synthesized via McMurry cross-coupling followed by copper-catalyzed [3 + 2] azide-alkyne cycloaddition of the fluorescent group coumarin. Cyclic voltammograms of P797 exhibit either a monoelectronic oxidation wave ascribed to the ferrocene Fe(II) → Fe(III) conversion or a three-electron oxidation process in the presence of a base, leading to a Fe(III) quinone methide adduct. This general sequence is consistent with those previously described for non-fluorescent ferrociphenols. Furthermore, the fluorescence properties of P797 and its oxidized intermediates appear to strongly depend on the redox state of the ferrocene group. Indeed, electrochemical generation of Fe(III) (ferrocenium) states markedly increases the fluorescence emission intensity. In contrast, the emission of the Fe(II) (ferrocene) states is partially quenched by photoinduced electron transfer (PET) from the Fe(II) donor to the coumarin acceptor and by concentration-dependent self-quenching. Owing to its switchable fluorescence properties, complex P797 could represent an innovative and useful tool to study the biodistribution and the redox state of ferrocifens in cancer cells

    Self-Assembling of Redox-Active Atrazine Poly(ethylenimine) Conjugates – Interfacial Electrochemical and Spectroscopic Characterization

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    International audienceThin films of polymers tethered with both atrazine haptens and ferrocenyl (Fc) probes were formed on polycrystalline gold electrodes by taking advantage of the facile formation of self-assembled monolayers (SAMs) of thiolates. These films were characterized by polarization modulation Fourier transform infrared reflection – absorption spectrometry (PM-IRRAS), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry. The combination of these techniques gave a full insight into the structure and the binding mode of the polymers and provided useful quantitative information about both Fc entity and atrazine hapten surface density. This may open the way to a new type of immunosensor for atrazine monitoring
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