The iron chaperone and nucleic acid–binding activities of poly(rC)-binding protein 1 are separable and independently essential

Poly(rC)-binding protein (PCBP1) is a multifunctional adaptor protein that can coordinate single-stranded nucleic acids and iron–glutathione complexes, altering the processing and transfer of these ligands through interactions with other proteins. Multiple phenotypes are ascribed to cells lacking PCBP1, but the relative contribution of RNA, DNA, or iron chaperone activity is not consistently clear. Here, we report the identification of amino acid residues required for iron coordination on each structural domain of PCBP1 and confirm the requirement of iron coordination for binding target proteins BolA2 and ferritin. We further construct PCBP1 variants that lack either nucleic acid– or iron-binding activity and examine their functions in human cells and mouse tissues depleted of endogenous PCBP1. We find that these activities are separable and independently confer essential functions. While iron chaperone activity controls cell cycle progression and suppression of DNA damage, RNA/DNA-binding activity maintains cell viability in both cultured cell and mouse models. The coevolution of RNA/DNA binding and iron chaperone activities on a single protein may prove advantageous for nucleic acid processing that depends on enzymes with iron cofactors.

Iron-Catalyzed Halogen Exchange of Trifluoromethyl Arenes

We report the facile production of ArCF₂X and ArCX₃from ArCF₃ using catalytic iron(III)halides, which constitutes the first iron-catalyzed halogen exchange for non-aromatic CF bonds. Theoretical calculations suggest direct activation of C–F bonds by iron coordination. ArCX₃ and ArCF₂X products of the reaction are synthetically valuable due to their diversification potential. In particular, bromo-, chloro-, and iododifluoromethyl arenes (ArCF₂Br, ArCF₂Cl, ArCF₂I, respectively) provide access to a myriad of difluoromethyl arene derivatives (ArCF₂R). To optimize for mono-halogen exchange, a statistical method called Design of Experiments was used. Optimized parameters were successfully applied to electron rich and electron deficient aromatic substrates, and to the late stage diversification of flufenoxuron, a commercial insecticide.

Iron-Catalyzed Halogen Exchange of Trifluoromethyl Arenes

We report the facile production of ArCF₂X and ArCX₃from ArCF₃ using catalytic iron(III)halides, which constitutes the first iron-catalyzed halogen exchange for non-aromatic CF bonds. Theoretical calculations suggest direct activation of C–F bonds by iron coordination. ArCX₃ and ArCF₂X products of the reaction are synthetically valuable due to their diversification potential. In particular, bromo-, chloro-, and iododifluoromethyl arenes (ArCF₂Br, ArCF₂Cl, ArCF₂I, respectively) provide access to a myriad of difluoromethyl arene derivatives (ArCF₂R). To optimize for mono-halogen exchange, a statistical method called Design of Experiments was used. Optimized parameters were successfully applied to electron rich and electron deficient aromatic substrates, and to the late stage diversification of flufenoxuron, a commercial insecticide.

Manganese Doped Iron Coordination Polymer Nanoparticles with Enhanced Peroxidase-like Activity for Colorimetric Detection of Antioxidants

Convenient and sensitive antioxidants assay with high-performance is essential for assessing food quality and monitoring the oxidative stress level of biological matrices. Although coordination polymer nanoparticles (CPNs)-based nanozymes have been...