H(+)-ATPsynthases couple a transmembrane proton transport with ATP synthesis and ATP hydrolysis. Previously, the relative subunit movement during this process has been measured by fluorescence resonance energy transfer (FRET) between two organic fluorophores covalently bound to different subunits. To improve the photophysical stability, a luminescent CdSe/ZnS nanocrystal (quantum dot) was bound to the enzyme and an organic fluorophore, Alexa568, was used as fluorescence acceptor. Single-molecule spectroscopy with the membrane integrated labeled H(+)-ATPsynthase was carried out. Single-pair FRET indicates three different conformations of the enzyme. During ATP hydrolysis relative intramolecular subunit movements are observed in real time.
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http://dx.doi.org/10.1007/s00249-008-0351-7 | DOI Listing |
J Fluoresc
January 2025
Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul, 01811, Korea.
We report a bithiophene-based fluorescence probe BDT (2,2'-(((1 E, 1'E)-[2,2'-bithiophene]-5,5'-diylbis(methaneylylidene))bis(azaneylylidene))bis(4-(tert-butyl)phenol)) for recognizing ClO. BDT selectively responded to ClO, leading to a blue fluorescence enhancement in a mixture of DMF/HEPES buffer (9:1, v/v). Importantly, BDT showed an ultrafast response (within 1 s) to ClO among the fluorescent turn-on chemosensors based on bithiophene.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Department of Physics, 845 W Taylor St, University of Illinois Chicago, Chicago, IL 60607, USA.
Altered DNA dynamics at lesion sites are implicated in how DNA repair proteins sense damage within genomic DNA. Using laser temperature-jump (T-jump) spectroscopy combined with cytosine-analog Förster Resonance Energy Transfer (FRET) probes that sense local DNA conformations, we measured the intrinsic dynamics of DNA containing 3 base-pair mismatches recognized in vitro by Rad4 (yeast ortholog of XPC). Rad4/XPC recognizes diverse lesions from environmental mutagens and initiates nucleotide excision repair.
View Article and Find Full Text PDFChem Asian J
January 2025
Universidad Austral de Chile, Instituto de Ciencias Químicas, CHILE.
Plasmonic materials can be utilized as effective platforms to enhance luminescent signals of luminescent metal nanoclusters (LMNCs). Both surface enhanced fluorescence (SEF) and shell-isolated nanoparticle-enhanced fluorescence (SHINEF) strategies take advantage of the localized and increased external electric field created around the plasmonic metal surface when excited at or near their characteristic plasmonic resonance. In this context, we present an experimental and computational study of different plasmonic composites, (Ag) Ag@SiO2 and (Au) Au@SiO2 nanoparticles, which were used to enhance the luminescent signal of Au nanoclusters coated with glutathione (GSH) molecule (Au25GSH NCs).
View Article and Find Full Text PDFDiagnostics (Basel)
January 2025
Department of Orthopedic Surgery, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo 409-3898, Yamanashi, Japan.
Angiomatoid fibrous histiocytoma (AFH) is a rare intermediate tumor that is often difficult to diagnose radiologically and pathologically. Herein, we report a case of AFH in the knee that was initially misdiagnosed as a cystic lesion. The tumor was first identified eight years earlier during the patient's initial visit, when plain magnetic resonance imaging (MRI) was performed, leading to a diagnosis of a cystic lesion.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
Zhejiang Cancer Hospital, Hangzhou Institute of Medicine, Chinese Academy of Sciences, Hangzhou 310022, PR China; School of Molecular Medicine, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, PR China.
Upconversion nanoparticles (UCNPs), as a type of light-emitting nanomaterials excited by near-infrared (NIR) light, can circumvent interference from spontaneous fluorescence and scattered light emitted by biological molecules in sensing applications. Traditional homogeneous core-shell UCNPs struggle to locate the position of luminescent doped ions (such as Tm) within the NaYF matrix, only the luminescent ions close to the surface of the particles can be efficiently quenched, with a low bursting efficiency that produces a considerable background. The full effectiveness energy transfer exists only by sufficiently close proximity between donor and acceptor.
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