High-field, heteronuclear NMR spectroscopy of biological macromolecules in native cellular environments is limited by the low concentrations present and the long data acquisition times needed for the experiments. Successful 1D and 2D heteronuclear NMR data have been reported, but the 3D experiments conventionally used for protein assignment and detailed characterization are generally too long to maintain cell viability. Here we describe the successful in vivo implementation of a suite of fast 3D NMR experiments which we have used to generate the complete backbone assignment of resonances in the recombinant polypeptide GB-1 within Escherichia coli cells. The data were acquired at 600 MHz with a cold probe using the projection reconstruction experiments, (3,2)HNCA, (3,2)HNCO, and (3,2)HA(CA)NH.
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http://dx.doi.org/10.1021/ja053145k | DOI Listing |
Protein 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 PDFInt J Biol Macromol
January 2025
Polymers Department, Faculty of Chemical Sciences, University of Concepción, Box 160-C, Concepción 4070371, Chile. Electronic address:
The contamination of water systems by antibiotics such as ciprofloxacin (CIP), which is used to treat bacterial infections, poses severe risks to environmental safety and public health. To address this issue, a novel zwitterionic polymeric nanocomposite (PNs-HTC) was developed in this study. This novel material was synthesized using alkylated chitosan ionic macromonomers, ionic monomers and combined with hydrotalcite (HTC) via in situ free radical polymerization.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Division of Pharmaceutics and Pharmacokinetics, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India. Electronic address:
Intratumoral drug delivery systems hold immense promise in overcoming the limitations of conventional IV chemotherapy, particularly in enhancing therapeutic efficacy and minimizing systemic side effects. In this study, we introduce a novel redox-responsive intratumoral nanogel system that combines the biocompatibility of natural polysaccharides with the tailored properties of synthetic polymers. The nanogel features a unique cross-linked architecture incorporating redox-sensitive segments, designed to leverage the elevated glutathione levels in the tumor microenvironment for controlled drug release.
View Article and Find Full Text PDFJ Biol Chem
January 2025
T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, 21218, USA. Electronic address:
Truncated hemoglobins (TrHbs) have an ancient origin and are widely distributed in microorganisms where they often serve roles other than dioxygen transport and storage. In extremophiles, these small heme proteins must have features that secure function under challenging conditions: at minimum, they must be folded, retain the heme group, allow substrates to access the heme cavity, and maintain their quaternary structure if present and essential. The genome of the obligate psychropiezophile Shewanella benthica strain KT99 harbors a gene for a TrHb belonging to a little-studied clade of globins (subgroup 2 of group N).
View Article and Find Full Text PDFChem Asian J
January 2025
East China University of Science and Technology, Institute of Fine Chemicals, Meilong Road, 200237, Shanghai, CHINA.
Oxidation of thia-pentapyrrane S-P4 with terminal β-linked pyrrole and thiophene units in the presence of various metal ions has been found to afford distinct porphyrinoids. Specifically, N-confused thiasapphyrin (1), Cu(III) norrole (2), neo-confused phlorin (3), and p-benzinorrole (4) were obtained, when S-P4 was oxidized with p-chloranil in acetonitrile in the presence of Ni2+, Cu2+, Cd2+, and Co2+, respectively. The structures of 1-4 have been clearly elucidated by NMR spectroscopy, HRMS, and X-ray crystal diffraction (for 2-4).
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