Deuterated C sites in sugars (D-glucose and 2-deoxy-D-glucose) showed 6.3-to-17.5-fold higher solid-state dynamic nuclear polarization (DNP) levels than their respective protonated sites at 3.35T. This effect was found to be unrelated to the protonation of the bath. Deuterated N in sites bound to exchangeable protons ([ N ]urea) showed a 1.3-fold higher polarization than their respective protonated sites at the same magnetic field. This relatively smaller effect was attributed to incomplete deuteration of the N sites due to the solvent mixture. For a N site that is not bound to protons or deuterons ([ N]nitrate), deuteration of the bath did not affect the polarization level. These findings suggest a phenomenon related to DNP of X-nuclei directly bound to deuteron(s) as opposed to proton(s). It appears that direct binding to deuterons increases the solid-state DNP polarization level of X-nuclei which are otherwise bound to protons.
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http://dx.doi.org/10.1002/cphc.202300144 | DOI Listing |
Nat Struct Mol Biol
January 2025
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
Transcription activators are said to stimulate gene expression by 'recruiting' coactivators, yet this vague term fits multiple kinetic models. To directly analyze the dynamics of activator-coactivator interactions, single-molecule microscopy was used to image promoter DNA, a transcription activator and the Spt-Ada-Gcn5 acetyltransferase (SAGA) complex within yeast nuclear extract. SAGA readily but transiently binds nucleosome-free DNA without an activator, while chromatin association occurs primarily when an activator is present.
View Article and Find Full Text PDFNat Chem
January 2025
State Key Laboratory of Advanced Drug Delivery and Release Systems, Liangzhu Laboratory, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.
Vesicles play critical roles in cellular materials storage and signal transportation, even in the formation of organelles and cells. Natural vesicles are composed of a lipid layer that forms a membrane for the enclosure of substances inside. Here we report a coacervate vesicle formed by the liquid-liquid phase separation of cholesterol-modified DNA and histones.
View Article and Find Full Text PDFEMBO J
January 2025
Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, 77030, USA.
Mitochondrial metabolism requires the chaperoned import of disulfide-stabilized proteins via CHCHD4/MIA40 and its enigmatic interaction with oxidoreductase Apoptosis-inducing factor (AIF). By crystallizing human CHCHD4's AIF-interaction domain with an activated AIF dimer, we uncover how NADH allosterically configures AIF to anchor CHCHD4's β-hairpin and histidine-helix motifs to the inner mitochondrial membrane. The structure further reveals a similarity between the AIF-interaction domain and recognition sequences of CHCHD4 substrates.
View Article and Find Full Text PDFCommun Chem
January 2025
Graduate School of Engineering, Hokkaido University, N13-W8, Kita-ku, Sapporo, Hokkaido, 060-8628, Japan.
Lactacystin is an irreversible proteasome inhibitor isolated from Streptomyces lactacystinicus. Despite its importance for its biological activity, the biosynthesis of lactacystin remains unknown. In this study, we identified the lactacystin biosynthetic gene cluster by gene disruption and heterologous expression experiments.
View Article and Find Full Text PDFNano Lett
January 2025
Corporate Research, TSMC, Hsinchu, 300-094, Taiwan.
Unprecedented penetration of artificial intelligence (AI) algorithms has brought about rapid innovations in electronic hardware, including new memory devices. Nonvolatile memory (NVM) devices offer one such attractive alternative with ∼2× density and data retention after powering off. Compute-in-memory (CIM) architectures further improve energy efficiency by fusing the computation operations with AI model storage.
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