Two-dimensional 1H-NMR spectra were carried out on bovine Cu(I),Zn superoxide dismutase. The ring protons of the single tyrosine and of the 4 phenylalanines were identified from COSY spectra. From NOESY spectra all imidazole C-resonances could be specifically assigned to each of the 8 histidines using the crystal coordinates of the Cu(II),Zn enzyme. Since 6 histidines are involved in the structure of the active site, this result implies nearly identical active site conformations for the two oxidation states of the catalytic cycle of this enzyme, in line with its diffusion-limited rate.
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http://dx.doi.org/10.1016/0014-5793(90)80720-4 | DOI Listing |
Inorg Chem
January 2025
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
The Pd-Zn γ-brass phase provides exciting opportunities for synthesizing site-isolated catalysts with precisely controlled Pd active site ensembles. Introducing a third metallic element into the γ-brass lattice further perturbs the catalytic active site ensembles. Here, we introduce coinage metallic elements M (M = Cu, Ag, and Au) into the Pd-Zn γ-brass phase and investigate the site occupation factors of each element in the γ-brass lattice.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Molecular Diagnostic Center, Key Laboratory of Clinical Cancer Pharmacology and Toxicology Research of Zhejiang Province, Hangzhou First People's Hospital, Hangzhou 310006, China.
The designability and high reactivity of nanotechnology provide strategies for antitumor therapy by regulating the redox state in tumor cells. Here, we synthesize a kind of vanadium dioxide nanoparticle encapsulated in bovine serum albumin and containing disulfide bonds (VSB NPs) for photothermal-enhanced ferroptosis and pyroptosis effects. Mechanism studies show that disulfide bonds can effectively consume overexpressed glutathione (GSH) in the tumor microenvironment, leading to a decrease in glutathione peroxidase 4 (GPX4) activity.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Basic Medical Sciences, Faculty of Medicine, Istanbul Medipol University, Istanbul 34815, Türkiye.
The COVID-19 pandemic began in March 2020 and has affected many countries and infected over a million people. It has had a serious impact on people's physical and mental health, daily life and the global economy. Today, many drugs show limited efficacy in the treatment of COVID-19 and studies to develop effective drugs continue.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Life Sciences and Systems Biology, University of Torino, Italy.
A new gene coding for an iron-containing enzyme was identified in the genome of Acinetobacter radioresistens. Bioinformatics analysis allowed the assignment of the protein to DyP peroxidases, due to the presence of conserved residues involved in heme binding and catalysis. Moreover, Ar-DyP is located in an operon coding also for other enzymes involved in iron uptake and regulation.
View Article and Find Full Text PDFStructure
January 2025
Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA. Electronic address:
High-risk human papillomavirus E6 oncoprotein is a model system for the recognition and degradation of cellular p53 tumor suppressor protein. There remains a gap in the understanding of the ubiquitin transfer reaction, including placement of the E6AP catalytic HECT domain of the ligase concerning the p53 substrate and how E6 itself is protected from ubiquitination. We determined the cryoelectron microscopy (cryo-EM) structure of the E6AP/E6/p53 complex, related the structure to in vivo modeling of the tri-molecular complex, and identified structural interactions associated with activation of the ubiquitin ligase function.
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