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Recent structures of full-length ATP-binding cassette (ABC) transporter MsbA in different states indicate large conformational changes during the reaction cycle that involve transient dimerization of its nucleotide-binding domains (NBDs). However, a detailed molecular understanding of the structural changes and associated kinetics of MsbA upon ATP binding and hydrolysis is still missing. Here, we employed time-resolved small-angle X-ray scattering, initiated by stopped-flow mixing, to investigate the kinetics and accompanying structural changes of NBD dimerization (upon ATP binding) and subsequent dissociation (upon ATP hydrolysis) in the context of isolated NBDs as well as full-length MsbA in lipid nanodiscs. Our data allowed us to structurally characterize the major states involved in the process and determine time constants for NBD dimerization and dissociation. In the full-length protein, these structural transitions occur on much faster time scales, indicating close-proximity effects and structural coupling of the transmembrane domains with the NBDs.
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http://dx.doi.org/10.1016/j.str.2019.12.001 | DOI Listing |
Biology (Basel)
August 2025
School of Basic Medicine, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, China.
Against the backdrop of rising multidrug-resistant (MDR AB) threats, this study explores the in vitro antibacterial activity and mechanism of (a Miao ethnic medicinal herb) crude extract. Using 10 clinical MDR AB strains, we reassessed antibiotic sensitivity and then applied microbroth dilution to determine MIC/MBC, time-kill curves for bactericidal kinetics, and SEM/TEM for structural changes. Proteomics identified downregulated proteins, cross-referenced with VFDB/CARD to target membrane-related proteins (msbA, lptD), while molecular docking validated the strong binding of linarin/hyperoside to these targets.
View Article and Find Full Text PDFSmall
September 2025
State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Ocean and Life Sciences, Dalian University of Technology, Panjin, 124221, China.
Doping induces lattice distortion and modifies the electronic structure of materials, thereby enhancing their electrical conductivity and chemical stability. The built-in electric field at heterojunction interfaces further promotes charge carrier migration and improves surface reaction kinetics. To leverage these synergistic effects, this study employs a combined approach involving sulfidation, phosphidation, and electrodeposition to achieve P-doping and construct a heterojunction layered structure.
View Article and Find Full Text PDFAnal Bioanal Chem
August 2025
Cancer Hospital of Dalian University of Technology, Dalian University of Technology, Shenyang, 110042, People's Republic of China.
Monodisperse polyethylene glycol (PEG) derivatives offer significant advantages over conventional polydisperse PEGs for biomedical applications due to their precisely defined molecular structures. This study establishes an eco-efficient, selective, and sensitive analytical assay integrating microscale solid-phase extraction (μ-SPE) with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) to investigate the cellular uptake of HO-PEG-OH polymers in MCF-7 cells. The method achieved greater than 91% recovery from 20 μL lysates using M-PEG-OH as the internal standard, with validated linearity (10-1000 ng/mL, R > 0.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2025
State Key Laboratory of Fine Chemicals, School of Chemistry, Frontier Science Center for Smart Materials, Dalian University of Technology, Dalian, 116024, China.
Co-catalysts integration presents unique opportunities to enhance photoactivity, yet selectivity control and mechanistic understanding within multistep reactions remain fundamental challenges hitherto. In this study, a reshaped kinetic landscape is demonstrated over coherently coupled surface frustrated Lewis pairs (FLPs) on carbon nitride matrix, which mediates directed CO-to-CH conversion with a selectivity of 65.3% (electron basis).
View Article and Find Full Text PDFBioengineering (Basel)
September 2024
Software College, Northeastern University, Shenyang 110169, China.
The automatic recognition and quantitative analysis of abnormal behavior in mice play a crucial role in behavioral observation experiments in neuroscience, pharmacology, and toxicology. Due to the challenging definition of abnormal behavior and difficulty in collecting training samples, directly applying behavior recognition methods to identify abnormal behavior is often infeasible. This paper proposes ABNet, an AI-empowered abnormal action recognition approach for mice.
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