Biochemical and structural insights into FIH-catalysed hydroxylation of transient receptor potential ankyrin repeat domains

Transient Receptor Potential (TRP) channels have important roles in environmental sensing in animals. Human TRP subfamily A member 1 (TRPA1) is responsible for sensing allyl isothiocyanate (AITC) and other electrophilic sensory irritants. TRP subfamily vanilloid member 3 (TRPV3) is involved in skin maintenance. TRPV3 is a reported substrate of the 2-oxoglutarate oxygenase factor inhibiting hypoxia inducible factor (FIH). We report biochemical and structural studies concerning asparaginyl hydroxylation of the ankyrin repeat domains (ARDs) of TRPA1 and TRPV3 catalysed by FIH. The results with ARD peptides support a previous report on FIH-catalysed TRPV3 hydroxylation and show that, of the 12 potential TRPA1 sequences investigated, one sequence (TRPA1 residues 322-348) undergoes hydroxylation at Asn-336. Structural studies reveal that the TRPA1 and TRPV3 ARDs bind to FIH with a similar overall geometry to most other reported FIH substrates. However, the binding mode of TRPV3 to FIH is distinct from that of other substrates

Bicyclic Boronate VNRX-5133 Inhibits Metallo- and Serine-β-Lactamases

The bicyclic boronate VNRX-5133 (taniborbactam) is a new type of β-lactamase inhibitor in clinical development. We report that VNRX-5133 inhibits serine-β-lactamases (SBLs) and some clinically important metallo-β-lactamases (MBLs), including NDM-1 and VIM-1/2. VNRX-5133 activity against IMP-1 and tested B2/B3 MBLs was lower/not observed. Crystallography reveals how VNRX-5133 binds to the class D SBL OXA-10 and MBL NDM-1. The crystallographic results highlight the ability of bicyclic boronates to inhibit SBLs and MBLs via binding of a tetrahedral (sp3) boron species. The structures imply conserved binding of the bicyclic core with SBLs/MBLs. With NDM-1, by crystallography, we observed an unanticipated VNRX-5133 binding mode involving cyclization of its acylamino oxygen onto the boron of the bicyclic core. Different side-chain binding modes for bicyclic boronates for SBLs and MBLs imply scope for side-chain optimization. The results further support the "high-energy-intermediate" analogue approach for broad-spectrum β-lactamase inhibitor development and highlight the ability of boron inhibitors to interchange between different hybridization states/binding modes

Demokratiebarometer: ein neues Instrument zur Messung von Demokratiequalität

Ziel dieses Artikels ist die Präsentation eines neuen Demokratieindex – des Demokratiebarometers. Das Demokratiebarometer versucht, die konzeptionellen und methodologischen S chwächen bisheriger Demokratiemaße zu überwinden, um so die Qualitätsunterschiede von etablierten Demokratien messen und analysieren zu können. Der Index basiert auf einem ausdifferenzierten Demokratiekonzept, aus dem in mehreren transparenten S chritten die Messindikatoren abgeleitet werden: Aus den drei konstituierenden Prinzipien F reiheit, Gleichheit und Kontrolle werden zunächst neun grundlegende F unktionen deduziert, aus denen dann Komponenten und daraus wiederum Subkomponenten und schließlich Indikatoren abgeleitet werden. Dieses Konzept wird in einem ersten S chritt dargelegt. Danach werden die methodologischen Grundlagen – die Messung und Aggregierung – des Demokratiebarometers erläutert. Die Präsentation erster Resultate sowie die E rgebnisse verschiedener Validitätstests zeigen schließlich die Plausibilität und das Potenzial dieses neuen Messinstruments auf