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1. Zinc-limited Mycobacterium tuberculosis stimulate distinct responses in macrophages compared with standard zinc-replete bacteria

   https://doi.org/10.1128/iai.00578-24  

   Marcantonio, Endrei; Burger, Allexa D; Chang, Kelly H; Hoffmann, Fukun W; Fu, Yuanyuan; Khadka, Vedbar S; Smagghe, Benoit J; Deng, Youping; Hoffmann, Peter R; Prisic, Sladjana (March 2025, Infection and Immunity)

   Shin, Sunny (Ed.)

   ABSTRACT Tuberculosis (TB) is notoriously difficult to treat, likely due to the complex host-pathogen interactions driven by pathogen heterogeneity. An understudied area of TB pathogenesis is host responses toMycobacterium tuberculosisbacteria (Mtb) that are limited in zinc ions. This distinct population resides in necrotic granulomas and sputum and could be the key player in tuberculosis pathogenicity. In this study, we tested the hypothesis that macrophages differentiate between Mtb grown under zinc limitation or in the standard zinc-replete medium. Using several macrophage infection models, such as murine RAW 264.7 and murine bone marrow-derived macrophages (BMDMs), as well as human THP-1-derived macrophages, we show that macrophages infected with zinc-limited Mtb have increased bacterial burden compared with macrophages infected with zinc-replete Mtb. We further demonstrate that macrophage infection with zinc-limited Mtb trigger higher production of reactive oxygen species (ROS) and cause more macrophage death. Furthermore, the increased ROS production is linked to the increased phagocytosis of zinc-limited Mtb, whereas cell death is not. Finally, transcriptional analysis of RAW 264.7 macrophages demonstrates that macrophages have more robust pro-inflammatory responses when infected with zinc-limited Mtb than zinc-replete Mtb. Together, our findings suggest that Mtb’s access to zinc affects their interaction with macrophages and that zinc-limited Mtb may be influencing TB progression. Therefore, zinc availability in bacterial growth medium should be considered in TB drug and vaccine developments. 

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2. Improved Photodecarboxylation Properties in Zinc Photocages Constructed Using m‐ Nitrophenylacetic Acid Variants**

   https://doi.org/10.1002/cptc.202200102  

   Shigemoto, Austin_K; Bhattacharjee, Avik; Hickey, Erin_E; Boyd, Hallee_Jade; McCormick, Theresa_M; Burdette, Shawn_C (June 2022, ChemPhotoChem)

   Abstract The methoxy‐ and fluoro‐derivatives ofmeta‐nitrophenylacetic acid (mNPA) chromophores undergo photodecarboxylation with comparable quantum yields (Φ) to unsubstitutedmNPA, but uncage at red‐shifted excitation wavelengths. This observation prompted us to investigate DPAdeCageOMe (2‐[bis(pyridin‐2‐ylmethyl)amino]‐2‐(4‐methoxy‐3‐nitrophenyl)acetic acid) and DPAdeCageF (2‐[bis(pyridin‐2‐ylmethyl)amino]‐2‐(4‐fluoro‐3‐nitrophenyl)acetic acid) as Zn²⁺photocages. DPAdeCageOMe has a high Φ and exhibits other photophysical properties comparable to XDPAdeCage ({bis[(2‐pyridyl)methyl]amino}(9‐oxo‐2‐xanthenyl) acetic acid), the best preforming Zn²⁺photocage reported to date. Since the synthesis of DPAdeCageOMe is more straightforward than XDPACage, the new photocage will be a highly competitive tool for biological applications. 

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3. Zinc K -edge XANES spectroscopy of mineral and organic standards

   https://doi.org/10.1107/S160057751900540X  

   Castorina, Erin; Ingall, Ellery D.; Morton, Peter L.; Tavakoli, David A.; Lai, Barry (July 2019, Journal of Synchrotron Radiation)

   Zinc K -edge X-ray absorption near-edge (XANES) spectroscopy was conducted on 40 zinc mineral samples and organic compounds. The K -edge position varied from 9660.5 to 9666.0 eV and a variety of distinctive peaks at higher post-edge energies were exhibited by the materials. Zinc is in the +2 oxidation state in all analyzed materials, thus the variations in edge position and post-edge features reflect changes in zinc coordination. For some minerals, multiple specimens from different localities as well as pure forms from chemical supply companies were examined. These specimens had nearly identical K -edge and post-edge peak positions with only minor variation in the intensity of the post-edge peaks. This suggests that typical compositional variations in natural materials do not strongly affect spectral characteristics. Organic zinc compounds also exhibited a range of edge positions and post-edge features; however, organic compounds with similar zinc coordination structures had nearly identical spectra. Zinc XANES spectral patterns will allow identification of unknown zinc-containing minerals and organic phases in future studies. 

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4. Zinc Binding Inhibits Cellular Uptake and Antifungal Activity of Histatin-5 in Candida albicans

   https://doi.org/10.1021/acsinfecdis.2c00289  

   Campbell, Joanna X.; Gao, Sean; Anand, Keerthi S.; Franz, Katherine J. (September 2022, ACS Infectious Diseases)
5. Structural and Spectroscopic Characterization of a Zinc-Bound N -Oxyphthalimide Radical

   https://doi.org/10.1021/acs.inorgchem.2c01765  

   Baeza Cinco, Miguel Á.; Wu, Guang; Telser, Joshua; Hayton, Trevor W. (August 2022, Inorganic Chemistry)