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As a novel avenue for applications, metal-organic frameworks (MOFs) are increasingly used for heterogenizing catalytic molecular species as linkers into their crystalline framework. These multifunctional compounds can be accessed with mixed linkers synthesis or postsynthetic-exchange strategies. Major limitations still reside in their challenging characterization; in particular, to provide evidence of the genuine incorporation of the functionalized linkers into the framework and their quantification. Herein, we demonstrate that a combination of computational chemistry, spectroscopy and X-ray diffraction allows access to a non-destructive analysis of mixed-linker UiO-67-type materials featuring biphenyl- and bipyridine-dicarboxylates. Our UV/Vis-based methodology has been further applied to characterize a series of Rh-functionalized UiO-67-type catalysts. The proposed approach allows a recurrent key issue in the characterization of similar supported organometallic systems to be solved. [ABSTRACT FROM AUTHOR]

We present herein the first example of metal-organic frameworks postfunctionalized with peptides. Our microwave-assisted postsynthetic modification method yields enantiopure peptides anchored inside MOF cavities. Al-MIL-101-NH2, In-MIL-68-NH2, and Zr-UiO-66-NH2 were chosen as starting platforms. A single amino acid and various oligopeptides are grafted with yields up to 60% after a 30 min microwave-assisted coupling-deprotection sequence. This allows efficient preparation of a library of functional hybrid solids for molecular recognition applications such as sensing, separation, or asymmetric catalysis, as demonstrated here for the chiral aldol reaction. [ABSTRACT FROM AUTHOR]

The first photosensitization of a rhodium-based catalytic system for CO2 reduction is reported, with formate as the sole carbon-containing product. Formate has wide industrial applications and is seen as valuable within fuel cell technologies as well as an interesting H2-storage compound. Heterogenization of molecular rhodium catalysts is accomplished via the synthesis, post-synthetic linker exchange, and characterization of a new metal-organic framework (MOF) Cp*Rh@UiO-67. While the catalytic activities of the homogeneous and heterogeneous systems are found to be comparable, the MOF-based system is more stable and selective. Furthermore it can be recycled without loss of activity. For formate production, an optimal catalyst loading of ~10% molar Rh incorporation is determined. Increased incorporation of rhodium catalyst favors thermal decomposition of formate into H2. There is no precedent for a MOF catalyzing the latter reaction so far. [ABSTRACT FROM AUTHOR]

A set of 15 metal–organic frameworks (MIL-53, MIL-68, MIL-125, UiO-66, ZIF) exhibiting different pore size, morphology, and surface chemistry is used to unravel the numerous behaviors of water adsorption at room temperature in this class of materials. Outstanding “S”-shaped (type V) adsorption isotherms are observed for MIL-68 type solids. We show that the underlying mechanism of water adsorption can be rationalized using a simple set of three parameters: the Henry constant (i.e. the slope of the adsorption pressure in the low pressure range), the pressure at which pore filling occurs, and the maximum water adsorption capacity. While the Henry constant and pore filling pressure mostly depend on the affinity of water for the surface chemistry and on pore size, respectively, these two parameters are correlated as they both reflect different aspects of the hydrophobicity–hydrophilicity of the material. For a given type of porous structure, the functionalization of the material by hydrophilic moieties such as hydrogen bonding groups (amine or aldehyde) systematically leads to an increase in the Henry constant concomitantly with a decrease in the pore filling pressure. As for the adsorption mechanism, we show that, for a given temperature, there is a critical diameter (Dc∼ 20 Å for water at room temperature) above which pore filling occurs through irreversible capillary condensation accompanied by capillary hysteresis loops. Below this critical diameter, pore filling is continuous and reversible unless the material exhibits some adsorption-induced flexibility. [ABSTRACT FROM AUTHOR]

Background: The aggregation of the baker's yeast prion Ure2p is at the origin of the [URE3] trait. The Q- and N-rich Nterminal part of the protein is believed to drive Ure2p assembly into fibrils of amyloid nature and the fibrillar forms of full-length Ure2p and its N-terminal part generated in vitro have been shown to induce [URE3] occurrence when introduced into yeast cells. This has led to the view that the fibrillar form of the N-terminal part of the protein is sufficient for the recruitment of constitutive Ure2p and that it imprints its amyloid structure to full-length Ure2p. Results: Here we generate a set of Ure2p N-terminal fragments, document their assembly and structural properties and compare them to that of full-length Ure2p. We identify the minimal region critical for the assembly of Ure2p N-terminal part into amyloids and show that such fibrils are unable to seed the assembly of full length Ure2p unlike fibrils made of intact Ure2p. Conclusion: Our results clearly indicate that fibrillar Ure2p shares no structural similarities with the amyloid fibrils made of Ure2p N-terminal part. Our results further suggest that the induction of [URE3] by fibrils made of full-length Ure2p is likely the consequence of fibrils growth by depletion of cytosolic Ure2p while it is the consequence of de novo formation of prion particles following, for example, titration within the cells of a specific set of molecular chaperones when fibrils made of Ure2p N-terminal domain are introduced within the cytoplasm. [ABSTRACT FROM AUTHOR]

Major elements highlight IFNα implication in type 1 diabetes (T1D) pathogenesis. While there is still no cure for this autoimmune disease, we aimed to evaluate the benefit of IFNα kinoid (IFN-K). This conjugated vaccine consisting of IFNα coupled to Keyhole limpet hemocyanin as a carrier protein elicits the production of polyclonal anti-IFNα neutralizing antibodies and has shown beneficial effects in a recent phase IIb trial in lupus (NCT02665364). Three independent experiments in NOD mice were performed to evaluate the activity of anti-IFNα neutralizing antibodies, conveyed either by maternal transfer or by passive or active immunization. Glycemia was monitored by a glucometer, neutralizing antibodies by the virus-induced cytopathic effect assay and H&E pancreas sections were evaluated in blind. In the first study, we compared T1D incidence in offsprings from IFN-K or KLH immunized mothers with sentinels. In the second study, mice were passively immunized with purified total IgG from sera collected in NOD mice immunized with IFN-K or KLH. Finally, active immunization was performed with IFN-K, KLH or PBS in combination with a squalene oil-in-water adjuvant. Mice were immunized at 5, 10 or 15 weeks of age. Anti-IFNα neutralizing antibodies were effectively conveyed from mothers to offspring, and levels decreased over time to completely disappear by month 3. In progeny from IFN-K immunized mice, despite transient and low amount of neutralizing antibodies, insulitis was decreased compared to control groups and T1D onset was delayed. In the second study, long-lasting administrations of total IgG comprising anti-IFNα neutralizing antibodies conferred protection towards T1D development, while total IgG from KLH-immunized mice did not. Finally, diabetes incidence was reduced when IFN K immunization started at week 10 of age. These different elements point out the need to neutralize IFNα during NOD lifetime to prevent T1D, and encourage us to evaluate IFN-K in newly diagnosed T1D patients. Disclosure: N. Caillot: None. F. Colaone: None. R. Bertrand: None. J. Da Silva: None. S. Hamdi: None. J. Bonnefoy: None. A. Lehuen: Board Member; Spouse/Partner; Inatheris. Consultant; Self; Neovacs. B.F. Boitard: None. G. Grouard-Vogel: None. [ABSTRACT FROM AUTHOR]