Metal-ion-responsive transcriptional regulators within the MerR family effectively discriminate between mono- and divalent metal ions. Herein we address the origin of the specificity of the CueR protein for monovalent metal ions. Several spectroscopic techniques were employed to study Ag(I) , Zn(II) , and Hg(II) binding to model systems encompassing the metal-ion-binding loop of CueR from E. coli and V. cholerae. In the presence of Ag(I) , a conserved cysteine residue displays a pKa value for deprotonation of the thiol that is close to the physiological pH value. This property is only observed with the monovalent metal ion. Quantum chemically optimized structures of the CueR metal site with Cys 112 protonated demonstrate that the conserved Ser 77 backbone carbonyl oxygen atom from the other monomer of the homodimer is "pulled" towards the metal site. A common allosteric mechanism of the metalloregulatory members of the MerR family is proposed. For CueR, the mechanism relies on the protonation of Cys 112.
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http://dx.doi.org/10.1002/anie.201508555 | DOI Listing |
Int J Mol Sci
December 2024
Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dubravska cesta 9, 840 05 Bratislava, Slovakia.
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a highly arrhythmogenic syndrome triggered by stress, primarily linked to gain-of-function point mutations in the cardiac ryanodine receptor (RyR2). Flecainide, as an effective therapy for CPVT, is a known blocker of the surface-membrane Na channel, also affecting the intracellular RyR2 channel. The therapeutic relevance of the flecainide-RyR2 interaction remains controversial, as flecainide blocks only the RyR2 current flowing in the opposite direction to the physiological Ca release from the sarcoplasmic reticulum (SR).
View Article and Find Full Text PDFJ Org Chem
January 2025
Department of Medical Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland.
There has been a long search for a simple preparation of new cyclic analogues of ionophore antibiotics. We report a simple and general synthesis of three new cyclic derivatives of polyether ionophore, monensin A (MON). The application of the Huisgen 1,3-dipolar cycloaddition of azides and terminal alkynes to macrocyclization results in a concise, synthetic route to monensin lacton or lactam in only 4 steps.
View Article and Find Full Text PDFCurr Mol Med
January 2025
Department of Radiation Science, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
Background: The anticancer activity and radiosensitizing effect of Auranofin, an an-tirheumatic and an approved gold metallic drug, have been investigated from multiple perspectives. In this study, the action of the new gold complex compound TPN-Au(I)-MM4 was compared with that of auranofin.
Methods: The inhibitory effect of 10 μM and 50 μM concentrations on cell proliferation was investigated using the human colon cancer cell lines HCT116 and SW480.
Angew Chem Int Ed Engl
January 2025
CNRS: Centre National de la Recherche Scientifique, Chemistry, FRANCE.
Compounds featuring bonds between mercury and transition metals are of interest for their intriguing/ambiguous bonding and scarcely explored reactivities. We report herein the synthesis and reactivities of the new compound [(POCOP)Ni]2Hg, [Ni2Hg], featuring a trinuclear Ni-Hg-Ni core (POCOP = κP,κC,κP´-2,6-(i-Pr2PO)2C6H3). [Ni2Hg] reacts with CO2 to give the carbonate-bridged complex [Ni2CO3].
View Article and Find Full Text PDFSci Technol Adv Mater
November 2024
Faculty of Materials Science and Engineering, Kyoto Institute of Technology, Kyoto, Japan.
We introduce our proprietary Materials Informatics (MI) technologies and our chemistry-oriented methodology for exploring new inorganic functional materials. Using machine learning on crystal structure databases, we developed 'Element Reactivity Maps' that displays the presence or the predicted formation probability of compounds for combinations of 80 × 80 × 80 elements. By analysing atomic coordinates with Delaunay tetrahedral decomposition, we established the concept of Delaunay Chemistry.
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