Naturally occurring metallothionein (MT) is a metal binding protein, which binds to seven Zn2+ through 20 conserved cysteines and forms two metal binding clusters with a Zinc-Blende structure. We demonstrate that the MT, when substituting the Zn2+ ions by Mn2+ and Cd2+, exhibits magnetic hysteresis loop observable by SQUID from 10 to 330 K. The magnetic moment may have originated from the bridging effect of the sulfur atoms between the metal ions that leads to the alignment of the electron spins of the Mn2+ ions inside the clusters. The protein backbone may restrain the net spin moment of Mn2+ ions from thermal fluctuation. The modified magnetic-metallothionein is a novel approach to creating molecular magnets with operating temperatures up to 330 K.
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http://dx.doi.org/10.1016/j.bbrc.2005.12.117 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Fudan University, Department of Macromolecular Science, 2205 Songhu Rd, 200438, Shanghai, CHINA.
Nitrogen heterocyclic carbenes (NHCs) are emerging as effective substitutes for conventional thiol ligands in surface functionalization of nanoparticles (NPs), offering exceptional stability to NPs under harsh conditions. However, the highly reactive feature of NHCs limits their use in introducing chemically active groups onto the NP surface. Herein, we develop a general yet robust strategy for the efficient surface functionalization of NPs with copolymer ligands bearing various functional groups.
View Article and Find Full Text PDFProtein Sci
February 2025
Department of Chemistry and Biochemistry, Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA.
Loz1 is a zinc-responsive transcription factor in fission yeast that maintains cellular zinc homeostasis by repressing the expression of genes required for zinc uptake in high zinc conditions. Previous deletion analysis of Loz1 found a region containing two tandem CH zinc-fingers and an upstream "accessory domain" rich in histidine, lysine, and arginine residues to be sufficient for zinc-dependent DNA binding and gene repression. Here we report unexpected biophysical properties of this pair of seemingly classical CH zinc fingers.
View Article and Find Full Text PDFProtein Sci
February 2025
Department of Physics, University of Washington, Seattle, Washington, USA.
Proteins' flexibility is a feature in communicating changes in cell signaling instigated by binding with secondary messengers, such as calcium ions, associated with the coordination of muscle contraction, neurotransmitter release, and gene expression. When binding with the disordered parts of a protein, calcium ions must balance their charge states with the shape of calcium-binding proteins and their versatile pool of partners depending on the circumstances they transmit. Accurately determining the ionic charges of those ions is essential for understanding their role in such processes.
View Article and Find Full Text PDFEnviron Pollut
January 2025
School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China.
The interaction between dissolved organic matter (DOM) and ferrihydrite (Fh) is a crucial process to control the environmental behavior of heavy metals (HMs) in soil environments, with DOM playing a particularly strong role in HMs fate. Since chemical properties of DOM vary based on different soil parent materials, the underlying impact of DOM-Fh associations on HMs binding remains unclear. This study systematically investigated the interactions between DOM from three soil parent materials (fluvial alluvium: FDOM, sand-shale: SDOM and granite: GDOM) and Fh, and meanwhile understand their effects on the environmental behavior of Cd and Pb under various environmental conditions.
View Article and Find Full Text PDFJ Mol Biol
January 2025
Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA; Biology Department, Brookhaven National Laboratory, Upton, NY, USA. Electronic address:
Metals are essential elements in all living organisms, binding to approximately 50% of proteins. They serve to stabilize proteins, catalyze reactions, regulate activities, and fulfill various physiological and pathological functions. While there have been many advancements in determining the structures of protein-metal complexes, numerous metal-binding proteins still need to be identified through computational methods and validated through experiments.
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